1
|
Wu W, Sun S, Tang CS, Wu J, Ma Y, Zhang L, Cai C, Zhong J, Milošević MV, Wee ATS, Yin X. Realization of a 2D Lieb Lattice in a Metal-Inorganic Framework with Partial Flat Bands and Topological Edge States. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2405615. [PMID: 39180271 DOI: 10.1002/adma.202405615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 08/05/2024] [Indexed: 08/26/2024]
Abstract
Flat bands and Dirac cones in materials are the source of the exotic electronic and topological properties. The Lieb lattice is expected to host these electronic structures, arising from quantum destructive interference. Nevertheless, the experimental realization of a 2D Lieb lattice remained challenging to date due to its intrinsic structural instability. After computationally designing a Platinum-Phosphorus (Pt-P) Lieb lattice, it has successfully overcome its structural instability and synthesized on a gold substrate via molecular beam epitaxy. Low-temperature scanning tunneling microscopy and spectroscopy verify the Lieb lattice's morphology and electronic flat bands. Furthermore, topological Dirac edge states stemming from pronounced spin-orbit coupling induced by heavy Pt atoms are predicted. These findings convincingly open perspectives for creating metal-inorganic framework-based atomic lattices, offering prospects for strongly correlated phases interplayed with topology.
Collapse
Affiliation(s)
- Wenjun Wu
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Shuo Sun
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Chi Sin Tang
- Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Jing Wu
- Institute of Materials Research and Ring (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore, 138634, Singapore
| | - Yu Ma
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Lingfeng Zhang
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Chuanbing Cai
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Jianxin Zhong
- Center for Quantum Science and Technology, Department of Physics, Shanghai University, Shanghai, 200444, China
| | - Milorad V Milošević
- Department of Physics & NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Andrew T S Wee
- Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research, National University of Singapore, Singapore, 117546, Singapore
| | - Xinmao Yin
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| |
Collapse
|
2
|
Zhao L, Hua C, Song C, Yu W, Jiang W. Realization of skyrmion shift register. Sci Bull (Beijing) 2024; 69:2370-2378. [PMID: 38960814 DOI: 10.1016/j.scib.2024.05.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 04/15/2024] [Accepted: 05/23/2024] [Indexed: 07/05/2024]
Abstract
The big data explosion demands novel data storage technology. Among many different approaches, solitonic racetrack memory devices hold great promise for accommodating nonvolatile and low-power functionalities. As representative topological solitons, magnetic skyrmions are envisioned as potential information carriers for efficient information processing. While their advantages as memory and logic elements have been vastly exploited from theoretical perspectives, the corresponding experimental efforts are rather limited. These challenges, which are key to versatile skyrmionic devices, will be studied in this work. Through patterning concaved surface topography with designed arrays of indentations on standard Si/SiO2 substrates, we demonstrate that the resultant non-flat energy landscape could lead to the formation of hexagonal and square skyrmion lattices in Ta/CoFeB/MgO multilayers. Based on these films, one-dimensional racetrack devices are subsequently fabricated, in which a long-distance deterministic shifting of skyrmions between neighboring indentations is achieved at room temperature. Through separating the word line and the bit line, a prototype shift register device, which can sequentially generate and precisely shift complex skyrmionic data strings, is presented. The deterministic writing and long-distance shifting of skyrmionic bits can find potential applications in transformative skyrmionic memory, logic as well as the in-memory computing devices.
Collapse
Affiliation(s)
- Le Zhao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Chensong Hua
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Chengkun Song
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Weichao Yu
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China.
| | - Wanjun Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
3
|
Asmara TC, Green RJ, Suter A, Wei Y, Zhang W, Knez D, Harris G, Tseng Y, Yu T, Betto D, Garcia-Fernandez M, Agrestini S, Klein YM, Kumar N, Galdino CW, Salman Z, Prokscha T, Medarde M, Müller E, Soh Y, Brookes NB, Zhou KJ, Radovic M, Schmitt T. Emergence of Interfacial Magnetism in Strongly-Correlated Nickelate-Titanate Superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2310668. [PMID: 39101291 DOI: 10.1002/adma.202310668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 06/21/2024] [Indexed: 08/06/2024]
Abstract
Strongly-correlated transition-metal oxides are widely known for their various exotic phenomena. This is exemplified by rare-earth nickelates such as LaNiO3, which possess intimate interconnections between their electronic, spin, and lattice degrees of freedom. Their properties can be further enhanced by pairing them in hybrid heterostructures, which can lead to hidden phases and emergent phenomena. An important example is the LaNiO3/LaTiO3 superlattice, where an interlayer electron transfer has been observed from LaTiO3 into LaNiO3 leading to a high-spin state. However, macroscopic emergence of magnetic order associated with this high-spin state has so far not been observed. Here, by using muon spin rotation, x-ray absorption, and resonant inelastic x-ray scattering, direct evidence of an emergent antiferromagnetic order with high magnon energy and exchange interactions at the LaNiO3/LaTiO3 interface is presented. As the magnetism is purely interfacial, a single LaNiO3/LaTiO3 interface can essentially behave as an atomically thin strongly-correlated quasi-2D antiferromagnet, potentially allowing its technological utilization in advanced spintronic devices. Furthermore, its strong quasi-2D magnetic correlations, orbitally-polarized planar ligand holes, and layered superlattice design make its electronic, magnetic, and lattice configurations resemble the precursor states of superconducting cuprates and nickelates, but with an S→1 spin state instead.
Collapse
Affiliation(s)
- Teguh Citra Asmara
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869, Schenefeld, Germany
| | - Robert J Green
- Department of Physics & Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Andreas Suter
- Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Yuan Wei
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Wenliang Zhang
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Daniel Knez
- Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, Graz, 8010, Austria
| | - Grant Harris
- Department of Physics & Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Yi Tseng
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Tianlun Yu
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Davide Betto
- European Synchrotron Radiation Facility, 71, avenue des Martyrs, Cedex 9, Grenoble, F-38043, France
| | - Mirian Garcia-Fernandez
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Stefano Agrestini
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Yannick Maximilian Klein
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Neeraj Kumar
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Carlos William Galdino
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Zaher Salman
- Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Thomas Prokscha
- Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Marisa Medarde
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Elisabeth Müller
- Electron Microscopy Facility, Paul Scherrer Institut, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Yona Soh
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Nicholas B Brookes
- European Synchrotron Radiation Facility, 71, avenue des Martyrs, Cedex 9, Grenoble, F-38043, France
| | - Ke-Jin Zhou
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Milan Radovic
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| | - Thorsten Schmitt
- PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland
| |
Collapse
|
4
|
Gao FY, Peng X, Cheng X, Viñas Boström E, Kim DS, Jain RK, Vishnu D, Raju K, Sankar R, Lee SF, Sentef MA, Kurumaji T, Li X, Tang P, Rubio A, Baldini E. Giant chiral magnetoelectric oscillations in a van der Waals multiferroic. Nature 2024; 632:273-279. [PMID: 39020169 PMCID: PMC11306099 DOI: 10.1038/s41586-024-07678-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 06/05/2024] [Indexed: 07/19/2024]
Abstract
Helical spin structures are expressions of magnetically induced chirality, entangling the dipolar and magnetic orders in materials1-4. The recent discovery of helical van der Waals multiferroics down to the ultrathin limit raises prospects of large chiral magnetoelectric correlations in two dimensions5,6. However, the exact nature and magnitude of these couplings have remained unknown so far. Here we perform a precision measurement of the dynamical magnetoelectric coupling for an enantiopure domain in an exfoliated van der Waals multiferroic. We evaluate this interaction in resonance with a collective electromagnon mode, capturing the impact of its oscillations on the dipolar and magnetic orders of the material with a suite of ultrafast optical probes. Our data show a giant natural optical activity at terahertz frequencies, characterized by quadrature modulations between the electric polarization and magnetization components. First-principles calculations further show that these chiral couplings originate from the synergy between the non-collinear spin texture and relativistic spin-orbit interactions, resulting in substantial enhancements over lattice-mediated effects. Our findings highlight the potential for intertwined orders to enable unique functionalities in the two-dimensional limit and pave the way for the development of van der Waals magnetoelectric devices operating at terahertz speeds.
Collapse
Affiliation(s)
- Frank Y Gao
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX, USA
| | - Xinyue Peng
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX, USA
| | - Xinle Cheng
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - Emil Viñas Boström
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Nano-Bio Spectroscopy Group, Departamento de Física de Materiales, Universidad del País Vasco, San Sebastián, Spain
| | - Dong Seob Kim
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX, USA
| | - Ravish K Jain
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Deepak Vishnu
- Institute of Physics, Academia Sinica, Taipei, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
| | | | - Raman Sankar
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Shang-Fan Lee
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Michael A Sentef
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Institute for Theoretical Physics and Bremen Center for Computational Materials Science, University of Bremen, Bremen, Germany
| | - Takashi Kurumaji
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - Xiaoqin Li
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX, USA
| | - Peizhe Tang
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- Nano-Bio Spectroscopy Group, Departamento de Física de Materiales, Universidad del País Vasco, San Sebastián, Spain.
- Center for Computational Quantum Physics, The Flatiron Institute, New York, NY, USA.
| | - Edoardo Baldini
- Department of Physics and Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX, USA.
| |
Collapse
|
5
|
Nadeem M, Wang X. Spin Gapless Quantum Materials and Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2402503. [PMID: 38962884 DOI: 10.1002/adma.202402503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 06/04/2024] [Indexed: 07/05/2024]
Abstract
Quantum materials, with nontrivial quantum phenomena and mechanisms, promise efficient quantum technologies with enhanced functionalities. Quantum technology is held back because a gap between fundamental science and its implementation is not fully understood yet. In order to capitalize the quantum advantage, a new perspective is required to figure out and close this gap. In this review, spin gapless quantum materials, featured by fully spin-polarized bands and the electron/hole transport, are discussed from the perspective of fundamental understanding and device applications. Spin gapless quantum materials can be simulated by minimal two-band models and could help to understand band structure engineering in various topological quantum materials discovered so far. It is explicitly highlighted that various types of spin gapless band dispersion are fundamental ingredients to understand quantum anomalous Hall effect. Based on conventional transport in the bulk and topological transport on the boundaries, various spintronic device aspects of spin gapless quantum materials as well as their advantages in different models for topological field effect transistors are reviewed.
Collapse
Affiliation(s)
- Muhammad Nadeem
- Institute for Superconducting and Electronic Materials (ISEM), Faculty of Engineering and Information Sciences (EIS), University of Wollongong, Wollongong, New South Wales, 2525, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), University of Wollongong, Wollongong, New South Wales, 2525, Australia
| | - Xiaolin Wang
- Institute for Superconducting and Electronic Materials (ISEM), Faculty of Engineering and Information Sciences (EIS), University of Wollongong, Wollongong, New South Wales, 2525, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), University of Wollongong, Wollongong, New South Wales, 2525, Australia
| |
Collapse
|
6
|
Suresh S, Sadhu SPP, Mishra V, Paulus W, Ramachandra Rao MS. Tunable charge transport properties in non-stoichiometric SrIrO 3thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:425601. [PMID: 38981585 DOI: 10.1088/1361-648x/ad6111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 07/09/2024] [Indexed: 07/11/2024]
Abstract
Delving into the intricate interplay between spin-orbit coupling and Coulomb correlations in strongly correlated oxides, particularly perovskite compounds, has unveiled a rich landscape of exotic phenomena ranging from unconventional superconductivity to the emergence of topological phases. In this study, we have employed pulsed laser deposition technique to grow SrIrO3(SIO) thin films on SrTiO3substrates, systematically varying the oxygen content during the post-deposition annealing. X-ray photoelectron spectroscopy (XPS) provided insights into the stoichiometry and spin-orbit splitting energy of Iridium within the SIO film, while high-resolution x-ray studies meticulously examined the structural integrity of the thin films. Remarkably, our findings indicate a decrease in the metallicity of SIO thin films with reduced annealing O2partial pressure. Furthermore, we carried out magneto-transport studies on the SIO thin films, the results revealed intriguing insights into spin transport as a function of oxygen content. The tunability of the electronic band structure of SIO films with varying oxygen vacancy is correlated with the density functional theory calculations. Our findings elucidate the intricate mechanisms dictating spin transport properties in SIO thin films, offering invaluable guidance for the design and optimization of spintronic devices based on complex oxide materials. Notably, the ability to tune bandwidth by varying post-annealing oxygen partial pressure in iridate-based spintronic materials holds significant promise for advancing technological applications in the spintronics domain.
Collapse
Affiliation(s)
- Sreya Suresh
- Department of Physics, Nano Functional Materials Technology Centre, Quantum Centre of Excellence for Diamond and Emergent Materials, and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Sai Pavan Prashanth Sadhu
- Department of Physics, Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram, Chennai 600 127, India
| | - Vikash Mishra
- Department of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka 576 104, India
| | - Werner Paulus
- ICGM, Univ Montpellier, CNRS, ENSCM, 34000, Montpellier, France
| | - M S Ramachandra Rao
- Department of Physics, Nano Functional Materials Technology Centre, Quantum Centre of Excellence for Diamond and Emergent Materials, and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai 600 036, India
| |
Collapse
|
7
|
De A, Pal S, Hellwig O, Barman A. Spin-wave dynamics in perpendicularly magnetized antidot multilayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:415802. [PMID: 38955338 DOI: 10.1088/1361-648x/ad5e54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/01/2024] [Indexed: 07/04/2024]
Abstract
Using all-optical time-resolved magneto-optical Kerr effect measurements we demonstrate an efficient modulation of the spin-wave (SW) dynamics via the bias magnetic field orientation around nanoscale diamond shaped antidots that are arranged on a square lattice within a [Co(0.75 nm)/Pd(0.9 nm)]8multilayer with perpendicular magnetic anisotropy (PMA). Micromagnetic modeling of the experimental results reveals that the SW modes in the lower frequency regime are related to narrow shell regions around the antidots, where in-plane (IP) domain structures are formed due to the reduced PMA, caused by Ga+ion irradiation during the focused ion beam milling process of antidot fabrication. The IP direction of the shell magnetization undergoes a striking change with magnetic field orientation, leading to the sharp variation of the edge localized (shell) SW modes. Nevertheless, the coupling between such edge localized and bulk SWs for different orientations of bias field in PMA systems gives rise to interesting Physics and attests to new prospects for developing energy efficient and hybrid-system-based next-generation nanoscale magnonic devices.
Collapse
Affiliation(s)
- Anulekha De
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, 67663 Kaiserslautern, Germany
| | - Semanti Pal
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
- Department of Physics, East Calcutta Girls' College, Kolkata 700089, India
| | - Olav Hellwig
- Institute of Physics, Chemnitz University of Technology, Chemnitz 09107, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Anjan Barman
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India
| |
Collapse
|
8
|
Guo Y, Zhuo F, Li H. Influence of the Hall-bar geometry on texture-induced topological spin transport in two-dimensional Rashba spin-orbit ferromagnets. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:415801. [PMID: 38959901 DOI: 10.1088/1361-648x/ad5eea] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 07/03/2024] [Indexed: 07/05/2024]
Abstract
While the recent prediction and observation of magnetic skyrmions bears inspiring promise for next-generation spintronic devices, how to detect and track their position becomes an important issue. In this work, we investigate the spin transport in a two-dimensional magnetic nanoribbon with the Hall-bar geometry in the presence of Rashba spin-orbit coupling and magnetic skyrmions. We employ the Kwant tight-binding code to compute the Hall conductance and local spin-polarized current density. We consider two versions of the model: One with single skyrmion and one with two separate skyrmions. It is found that the size and position of the skyrmions strongly modulate the Hall conductance near the Hall-bar position. The geometry of the Hall bar also has a strong influence on the Hall conductance of the system. With the decreasing of the width of Hall leads, the peak of Hall conductance becomes sharper. We also show the spatial distribution of the spin-polarized current density around a skyrmion located at different positions. We extend this study toward two separate skyrmions, where the Hall conductance also reveals a sizable dependence on the position of the skyrmions and their distance. Our numerical analysis offers the possibility of electrically detecting the skyrmion position, which could have potential applications in ultrahigh-density storage design.
Collapse
Affiliation(s)
- Yufei Guo
- School of Physics and Electronics, Henan University, Kaifeng 475004, People's Republic of China
| | - Fengjun Zhuo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Hang Li
- School of Physics and Electronics, Henan University, Kaifeng 475004, People's Republic of China
| |
Collapse
|
9
|
Bhattacharya S, Datta S. Rashba splitting in polar-nonpolar sandwich heterostructure: a DFT study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:405701. [PMID: 38979851 DOI: 10.1088/1361-648x/ad5d42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 06/28/2024] [Indexed: 07/10/2024]
Abstract
In this study, we employ density functional theory based first-principles calculations to investigate the spin-orbit effects in the electronic structure of a polar-nonpolar sandwich heterostructure namelyLaAlO3/SrTiO3/LaAlO3. Our focus on theTi-3dbands reveals an inverted ordering of theSrTiO3-t2gorbital near the n-type interface, which is consistent with earlier experimental work. In contrast, toward the p-type interface, the orbital ordering aligns with the natural ordering ofSrTiO3orbitals, influenced by crystal field splitting. In the presence of SOC, a notable inter-orbital coupling betweent2gandegorbitals is observed within the tetragonal slab, a phenomenon not reported before in theSrTiO3-based 2D systems. Additionally, our observations highlight that the cubic Rashba splitting in this system surpasses the linear Rashba splitting, contrary to experimental findings. This comprehensive analysis contributes to a refined understanding of the role of orbital mixing in Rashba splitting in the sandwich oxide heterostructures.
Collapse
Affiliation(s)
- Sanchari Bhattacharya
- Department of Physics and Astronomy, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Sanjoy Datta
- Department of Physics and Astronomy, National Institute of Technology, Rourkela 769008, Odisha, India
| |
Collapse
|
10
|
Liu T, Adhikari Y, Wang H, Jiang Y, Hua Z, Liu H, Schlottmann P, Gao H, Weiss PS, Yan B, Zhao J, Xiong P. Chirality-Induced Magnet-Free Spin Generation in a Semiconductor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2406347. [PMID: 38926947 DOI: 10.1002/adma.202406347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/09/2024] [Indexed: 06/28/2024]
Abstract
Electrical generation and transduction of polarized electron spins in semiconductors (SCs) are of central interest in spintronics and quantum information science. While spin generation in SCs is frequently realized via electrical injection from a ferromagnet (FM), there are significant advantages in nonmagnetic pathways of creating spin polarization. One such pathway exploits the interplay of electron spin with chirality in electronic structures or real space. Here, utilizing chirality-induced spin selectivity (CISS), the efficient creation of spin accumulation in n-doped GaAs via electric current injection from a normal metal (Au) electrode through a self-assembled monolayer (SAM) of chiral molecules (α-helix l-polyalanine, AHPA-L), is demonstrated. The resulting spin polarization is detected as a Hanle effect in the n-GaAs, which is found to obey a distinct universal scaling with temperature and bias current consistent with chirality-induced spin accumulation. The experiment constitutes a definitive observation of CISS in a fully nonmagnetic device structure and demonstration of its ability to generate spin accumulation in a conventional SC. The results thus place key constraints on the physical mechanism of CISS and present a new scheme for magnet-free SC spintronics.
Collapse
Affiliation(s)
- Tianhan Liu
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yuwaraj Adhikari
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Yiyang Jiang
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Zhenqi Hua
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Haoyang Liu
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Pedro Schlottmann
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Hanwei Gao
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Paul S Weiss
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute and Departments of Bioengineering and Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Peng Xiong
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| |
Collapse
|
11
|
Muñiz Cano B, Gudín A, Sánchez-Barriga J, Clark O, Anadón A, Díez JM, Olleros-Rodríguez P, Ajejas F, Arnay I, Jugovac M, Rault J, Le Fèvre P, Bertran F, Mazhjoo D, Bihlmayer G, Rader O, Blügel S, Miranda R, Camarero J, Valbuena MA, Perna P. Rashba-like Spin Textures in Graphene Promoted by Ferromagnet-Mediated Electronic Hybridization with a Heavy Metal. ACS NANO 2024; 18:15716-15728. [PMID: 38847339 DOI: 10.1021/acsnano.4c02154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2024]
Abstract
Epitaxial graphene/ferromagnetic metal (Gr/FM) heterostructures deposited onto heavy metals have been proposed for the realization of spintronic devices because of their perpendicular magnetic anisotropy and sizable Dzyaloshinskii-Moriya interaction (DMI), allowing for both enhanced thermal stability and stabilization of chiral spin textures. However, establishing routes toward this goal requires the fundamental understanding of the microscopic origin of their unusual properties. Here, we elucidate the nature of the induced spin-orbit coupling (SOC) at Gr/Co interfaces on Ir. Through spin- and angle-resolved photoemission spectroscopy along with density functional theory, we show that the interaction of the heavy metals with the Gr layer via hybridization with the FM is the source of strong SOC in the Gr layer. Furthermore, our studies on ultrathin Co films underneath Gr reveal an energy splitting of ∼100 meV for in-plane and negligible for out-of-plane spin polarized Gr π-bands, consistent with a Rashba-SOC at the Gr/Co interface, which is either the fingerprint or the origin of the DMI. This mechanism vanishes at large Co thicknesses, where neither in-plane nor out-of-plane spin-orbit splitting is observed, indicating that Gr π-states are electronically decoupled from the heavy metal. The present findings are important for future applications of Gr-based heterostructures in spintronic devices.
Collapse
Affiliation(s)
- Beatriz Muñiz Cano
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Adrián Gudín
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Jaime Sánchez-Barriga
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Oliver Clark
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Alberto Anadón
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Jose Manuel Díez
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | | | - Fernando Ajejas
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Iciar Arnay
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Matteo Jugovac
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | - Julien Rault
- Synchrotron SOLEIL, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | | | | | - Donya Mazhjoo
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Gustav Bihlmayer
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Oliver Rader
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Stefan Blügel
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Rodolfo Miranda
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Julio Camarero
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | | | - Paolo Perna
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| |
Collapse
|
12
|
Ning Z, Qian J, Liu Y, Chen F, Zhang M, Deng L, Yuan X, Ge Q, Jin H, Zhang G, Peng W, Qiao S, Mu G, Chen Y, Li W. Coexistence of Ferromagnetism and Superconductivity at KTaO 3 Heterointerfaces. NANO LETTERS 2024; 24:7134-7141. [PMID: 38828962 DOI: 10.1021/acs.nanolett.4c02500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The coexistence of superconductivity and ferromagnetism is a long-standing issue in superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism presents significant challenges. Here, we report the observation of two-dimensional long-range ferromagnetic order in a KTaO3 heterointerface superconductor, showing the coexistence of superconductivity and ferromagnetism. Remarkably, our direct current superconducting quantum interference device measurements reveal an in-plane magnetization hysteresis loop persisting above room temperature. Moreover, first-principles calculations and X-ray magnetic circular dichroism measurements provide decisive insights into the origin of the observed robust ferromagnetism, attributing it to oxygen vacancies that localize electrons in nearby Ta 5d states. Our findings suggest KTaO3 heterointerfaces as time-reversal symmetry breaking superconductors, injecting fresh momentum into the exploration of the intricate interplay between superconductivity and magnetism enhanced by the strong spin-orbit coupling inherent to the heavy Ta in 5d orbitals.
Collapse
Affiliation(s)
- Zhongfeng Ning
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jiahui Qian
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yixin Liu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fan Chen
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingzhu Zhang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liwei Deng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinli Yuan
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Qingqin Ge
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Hua Jin
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Guanqun Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Peng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shan Qiao
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Mu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| |
Collapse
|
13
|
Li R, Jin C, Zhang X, Qu J, Zheng D, He W, Yang F, Zheng R, Bai H. Angular-dependent magnetoresistance modulated by interfacial magnetic state in Pt/LSMO heterostructures. Phys Chem Chem Phys 2024; 26:16891-16897. [PMID: 38833218 DOI: 10.1039/d4cp01175a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The interfaces between heavy metals and antiferromagnetic materials have garnered significant attention due to their interesting physical properties. La0.35Sr0.65MnO3 (LSMO), as a typical manganite, exhibits an antiferromagnetic ground state that can be controlled through epitaxial strain and interfacial spin-orbit coupling. In this work, we reported the diverse magnetoresistance, influenced by the interfacial magnetic state, in Pt (3 nm)/LSMO (6-20 nm) heterostructures. The strong spin-orbit coupling of Pt and Dzyaloshinskii-Moriya interaction alter the spin structure and enhance the electron scattering at the Pt/LSMO interface, resulting in positive magnetoresistance. The interfacial angular-dependent magnetoresistance modulated by the interfacial magnetic states was also observed in the Pt/LSMO (20 nm) heterostructures. Our findings contribute to a broader understanding of interfacial properties between heavy metals and antiferromagnetic manganites.
Collapse
Affiliation(s)
- Ruikang Li
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China.
| | - Chao Jin
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China.
| | - Xingmo Zhang
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jiangtao Qu
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Dongxing Zheng
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Wenxue He
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China.
- Center for Joint Quantum Studies, School of Science, Tianjin University, Tianjin 300350, China
| | - Fan Yang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China.
- Center for Joint Quantum Studies, School of Science, Tianjin University, Tianjin 300350, China
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Haili Bai
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China.
| |
Collapse
|
14
|
Shi G, Wang F, Liu Y, Li Z, Tan HR, Yang D, Soumyanarayanan A, Yang H. Field-Free Manipulation of Two-Dimensional Ferromagnet CrTe 2 by Spin-Orbit Torques. NANO LETTERS 2024. [PMID: 38856112 DOI: 10.1021/acs.nanolett.4c01366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Electrical manipulation of magnetic states in two-dimensional ferromagnetic systems is crucial in information storage and low-dimensional spintronics. Spin-orbit torque presents a rapid and energy-efficient method for electrical control of the magnetization. In this letter, we demonstrate a wafer-scale spin-orbit torque switching of two-dimensional ferromagnetic states. Using molecular beam epitaxy, we fabricate two-dimensional heterostructures composed of low crystal-symmetry WTe2 and ferromagnet CrTe2 with perpendicular anisotropy. By utilizing out-of-plane spins generated from WTe2, we achieve field-free switching of the CrTe2 perpendicular magnetization. The threshold switching current density in CrTe2/WTe2 is 1.2 × 106 A/cm2, 20 times smaller than that of the CrTe2/Pt control sample even with an external magnetic field. In addition, the switching behavior can be modulated by external magnetic fields and crystal symmetry. Our findings demonstrate a controllable and all-electric manipulation of perpendicular magnetization in a two-dimensional ferromagnet, representing a significant advancement toward the practical implementation of low-dimensional spintronic devices.
Collapse
Affiliation(s)
- Guoyi Shi
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Fei Wang
- Key Laboratory of Magnetic Molecules and Magnetic Information, Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030006, China
| | - Yakun Liu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Zhaohui Li
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Hui Ru Tan
- Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore 138634, Singapore
| | - Dongsheng Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Anjan Soumyanarayanan
- Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore 138634, Singapore
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| |
Collapse
|
15
|
Sun R, Park KS, Comstock AH, McConnell A, Chen YC, Zhang P, Beratan D, You W, Hoffmann A, Yu ZG, Diao Y, Sun D. Inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. NATURE MATERIALS 2024; 23:782-789. [PMID: 38491147 DOI: 10.1038/s41563-024-01838-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/14/2024] [Indexed: 03/18/2024]
Abstract
Coupling of spin and charge currents to structural chirality in non-magnetic materials, known as chirality-induced spin selectivity, is promising for application in spintronic devices at room temperature. Although the chirality-induced spin selectivity effect has been identified in various chiral materials, its Onsager reciprocal process, the inverse chirality-induced spin selectivity effect, remains unexplored. Here we report the observation of the inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. Using spin-pumping techniques, the inverse chirality-induced spin selectivity effect enables quantification of the magnitude of the longitudinal spin-to-charge conversion driven by chirality-induced spin selectivity in different chiral polymers. By widely tuning conductivities and supramolecular chiral structures via a printing method, we found a very long spin relaxation time of up to several nanoseconds parallel to the chiral axis. Our demonstration of the inverse chirality-induced spin selectivity effect suggests possibilities for elucidating the puzzling interplay between spin and chirality, and opens a route for spintronic applications using printable chiral assemblies.
Collapse
Affiliation(s)
- Rui Sun
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Kyung Sun Park
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Andrew H Comstock
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Aeron McConnell
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Yen-Chi Chen
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Peng Zhang
- Department of Chemistry, Duke University, Durham, NC, USA
| | - David Beratan
- Department of Chemistry, Duke University, Durham, NC, USA
| | - Wei You
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Axel Hoffmann
- Department of Materials Science & Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Zhi-Gang Yu
- Sivananthan Laboratories, Bolingbrook, Illinois, USA
| | - Ying Diao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Dali Sun
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA.
| |
Collapse
|
16
|
Sharma V, Negusse E, Kumar R, Budhani RC. Ferromagnetic resonance measurement with frequency modulation down to 2 K. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:063902. [PMID: 38836719 DOI: 10.1063/5.0190105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 05/20/2024] [Indexed: 06/06/2024]
Abstract
Ferromagnetic resonance (FMR) spectroscopy is a powerful technique to study the precessional dynamics of magnetization in thin film heterostructures. It provides valuable information about the mechanisms of exchange bias, spin angular momentum transfer across interfaces, and excitation of magnons. A key desirable feature of FMR spectrometers is the capability to study magnetization dynamics over a wide phase space of temperature (T), frequency (f), and magnetic field (B). The design, fabrication, and testing of such a spectrometer, which uses frequency modulation techniques for improved detection of microwave absorption, reduces heat load in the cryostat and allows simultaneous measurements of inverse spin Hall effect (ISHE) induced dc voltages, is described in this paper. The apparatus is based on a 2-port transmitted microwave signal measurement using a grounded co-planar waveguide. The input radio frequency (RF) signal, frequency modulated at a tunable f-band, excites spin precession in the sample, and the attenuated RF signal is measured phase sensitively. The sample stage, inserted in the bore of a superconducting solenoid, allows magnetic field and temperature variability of 0 to ±5 T and 2-310 K, respectively. We demonstrate the working of this Cryo-FMR and ISHE spectrometer on thin films of Ni80Fe20 and Fe60Co20B20 over a wide T, B, and f phase space.
Collapse
Affiliation(s)
- Vinay Sharma
- Department of Physics, Morgan State University, Baltimore, Maryland 21251, USA
| | - Ezana Negusse
- Department of Physics, Morgan State University, Baltimore, Maryland 21251, USA
| | - Ravinder Kumar
- Department of Physics, Morgan State University, Baltimore, Maryland 21251, USA
| | - Ramesh C Budhani
- Department of Physics, Morgan State University, Baltimore, Maryland 21251, USA
| |
Collapse
|
17
|
Vudya Sethu KK, Yasin F, Swerts J, Sorée B, De Boeck J, Kar GS, Garello K, Couet S. Spin-Orbit Torque Vector Quantification in Nanoscale Magnetic Tunnel Junctions. ACS NANO 2024; 18:13506-13516. [PMID: 38748456 DOI: 10.1021/acsnano.3c11289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Spin-orbit torques (SOT) allow ultrafast, energy-efficient toggling of magnetization state by an in-plane charge current for applications such as magnetic random-access memory (SOT-MRAM). Tailoring the SOT vector comprising of antidamping (TAD) and fieldlike (TFL) torques could lead to faster, more reliable, and low-power SOT-MRAM. Here, we establish a method to quantify the longitudinal (TAD) and transverse (TFL) components of the SOT vector and its efficiency χAD and χFL, respectively, in nanoscale three-terminal SOT magnetic tunnel junctions (SOT-MTJ). Modulation of nucleation or switching field (BSF) for magnetization reversal by SOT effective fields (BSOT) leads to the modification of SOT-MTJ hysteresis loop behavior from which χAD and χFL are quantified. Surprisingly, in nanoscale W/CoFeB SOT-MTJ, we find χFL to be (i) twice as large as χAD and (ii) 6 times as large as χFL in micrometer-sized W/CoFeB Hall-bar devices. Our quantification is supported by micromagnetic and macrospin simulations which reproduce experimental SOT-MTJ Stoner-Wohlfarth astroid behavior only for χFL > χAD. Additionally, from the threshold current for current-induced magnetization switching with a transverse magnetic field, we show that in SOT-MTJ, TFL plays a more prominent role in magnetization dynamics than TAD. Due to SOT-MRAM geometry and nanodimensionality, the potential role of nonlocal spin Hall spin current accumulated adjacent to the SOT-MTJ in the mediation of TFL and χFL amplification merits to be explored.
Collapse
Affiliation(s)
- Kiran Kumar Vudya Sethu
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
| | | | | | - Bart Sorée
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
- Physics Department, University of Antwerp, Groenenborgerlaan 171, Antwerpen B-2020, Belgium
| | - Johan De Boeck
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
| | | | - Kevin Garello
- CEA, CNRS, Grenoble INP, SPINTEC, Université Grenoble Alpes, 38054 Grenoble, France
| | | |
Collapse
|
18
|
Kashikar R, DeTellem D, Ghosh PS, Xu Y, Ma S, Witanachchi S, Phan MH, Lisenkov S, Ponomareva I. Coupling of the Structure and Magnetism to Spin Splitting in Hybrid Organic-Inorganic Perovskites. J Am Chem Soc 2024; 146:13105-13112. [PMID: 38690965 DOI: 10.1021/jacs.3c14744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Hybrid organic-inorganic perovskites are famous for the diversity of their chemical compositions, phases, phase transitions, and associated physical properties. We use a combination of experimental and computational techniques to reveal a strong coupling between structure, magnetism, and spin splitting in a representative of the largest family of hybrid organic-inorganic perovskites: the formates. With the help of first-principles simulations, we find spin splitting in both conduction and valence bands of [NH2NH3]Co(HCOO)3 induced by spin-orbit interactions, which can reach up to 14 meV. Our magnetic measurements reveal that this material exhibits canted antiferromagnetism below 15.5 K. The direction of the associated antiferromagnetic order parameter is strongly coupled with spin splitting in the centrosymmetric phase, allowing for the creation and annihilation of spin splitting through the application of a magnetic field. Furthermore, the structural phase transition to the experimentally observed polar Pna21 phase completely changes the aforementioned spin splitting and its coupling to magnetic degrees of freedom. This reveals that in [NH2NH3]Co(HCOO)3, the structure and magnetism are strongly coupled to spin splitting and can be manipulated through electric and magnetic fields. We believe that our findings offer an important step toward a fundamental understanding and practical applications of materials with coupled properties.
Collapse
Affiliation(s)
- Ravi Kashikar
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Derick DeTellem
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Partha Sarathi Ghosh
- Glass & Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - Yixuan Xu
- Department of Chemistry, University of North Texas, CHEM 305D, 1508 W Mulberry Street, Denton, Texas 76201, United States
| | - Shengqian Ma
- Department of Chemistry, University of North Texas, CHEM 305D, 1508 W Mulberry Street, Denton, Texas 76201, United States
| | - Sarath Witanachchi
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Manh-Huong Phan
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Sergey Lisenkov
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Inna Ponomareva
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| |
Collapse
|
19
|
Liu S, Xu K, Li X, Li Q, Yang J. Obtaining giant Rashba-Dresselhaus spin splitting in two-dimensional chiral metal-organic frameworks. Chem Sci 2024; 15:6916-6923. [PMID: 38725518 PMCID: PMC11077538 DOI: 10.1039/d3sc06636c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 04/04/2024] [Indexed: 05/12/2024] Open
Abstract
Two-dimensional (2D) nonmagnetic semiconductors with large Rashba-Dresselhaus (R-D) spin splitting at valence or conduction bands are attractive for magnetic-field-free spintronic applications. However, so far, the number of 2D R-D inorganic semiconductors has been quite limited, and the factors that determine R-D spin splitting as well as rational design of giant spin splitting, remain unclear. For this purpose, by exploiting 2D chiral metal-organic frameworks (CMOFs) as a platform, we theoretically develop a three-step screening method to obtain a series of candidate 2D R-D semiconductors with valence band spin splitting up to 97.2 meV and corresponding R-D coupling constants up to 1.37 eV Å. Interestingly, the valence band spin texture is reversible by flipping the chirality of CMOFs. Furthermore, five keys for obtaining giant R-D spin splitting in 2D CMOFs are successfully identified: (i) chirality, (ii) large spin-orbit coupling, (iii) narrow band gap, (iv) valence and conduction bands having the same symmetry at the Γ point, and (v) strong ligand field.
Collapse
Affiliation(s)
- Shanshan Liu
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
| | - Ke Xu
- Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, School of Physics and Electronic Engineering, Hubei University of Arts and Science Xiangyang 441053 China
| | - Xingxing Li
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
| | - Qunxiang Li
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
| | - Jinlong Yang
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
| |
Collapse
|
20
|
Arnoldi B, Zachritz SL, Hedwig S, Aeschlimann M, Monti OLA, Stadtmüller B. Revealing hidden spin polarization in centrosymmetric van der Waals materials on ultrafast timescales. Nat Commun 2024; 15:3573. [PMID: 38678075 PMCID: PMC11055871 DOI: 10.1038/s41467-024-47821-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 04/12/2024] [Indexed: 04/29/2024] Open
Abstract
One of the key challenges for spintronic and quantum technologies is to achieve active control of the spin angular momentum of electrons in nanoscale materials on ultrafast, femtosecond timescales. While conventional ferromagnetic materials and materials supporting spin texture suffer both from conceptional limitations in miniaturization and inefficiency of optical and electronic manipulation, non-magnetic centrosymmetric layered materials with hidden spin polarization may offer an alternative pathway to manipulate the spin degree of freedom by external stimuli. Here we demonstrate an approach for generating transient spin polarization on a femtosecond timescale in the otherwise spin-unpolarized band structure of the centrosymmetric 2H-stacked group VI transition metal dichalcogenide WSe2. Using ultrafast optical excitation of a fullerene layer grown on top of WSe2, we trigger an ultrafast interlayer electron transfer from the fullerene layer into the WSe2 crystal. The resulting transient charging of the C60/WSe2 interface leads to a substantial interfacial electric field that by means of spin-layer-valley locking ultimately creates ultrafast spin polarization without the need of an external magnetic field. Our findings open a novel pathway for true optical engineering of spin functionalities such as the sub-picosecond generation and manipulation of ultrafast spin currents in 2D heterostructures.
Collapse
Affiliation(s)
- B Arnoldi
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - S L Zachritz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - S Hedwig
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - M Aeschlimann
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany
| | - O L A Monti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Physics, University of Arizona, Tucson, AZ, 85721, USA.
| | - B Stadtmüller
- Department of Physics and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Erwin-Schroedinger-Strasse 46, Kaiserslautern, 67663, Germany.
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128, Mainz, Germany.
| |
Collapse
|
21
|
Chen J, Koc H, Zhao S, Wang K, Chao L, Eginligil M. Emerging Nonlinear Photocurrents in Lead Halide Perovskites for Spintronics. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1820. [PMID: 38673177 PMCID: PMC11051301 DOI: 10.3390/ma17081820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/07/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024]
Abstract
Lead halide perovskites (LHPs) containing organic parts are emerging optoelectronic materials with a wide range of applications thanks to their high optical absorption, carrier mobility, and easy preparation methods. They possess spin-dependent properties, such as strong spin-orbit coupling (SOC), and are promising for spintronics. The Rashba effect in LHPs can be manipulated by a magnetic field and a polarized light field. Considering the surfaces and interfaces of LHPs, light polarization-dependent optoelectronics of LHPs has attracted attention, especially in terms of spin-dependent photocurrents (SDPs). Currently, there are intense efforts being made in the identification and separation of SDPs and spin-to-charge interconversion in LHP. Here, we provide a comprehensive review of second-order nonlinear photocurrents in LHP in regard to spintronics. First, a detailed background on Rashba SOC and its related effects (including the inverse Rashba-Edelstein effect) is given. Subsequently, nonlinear photo-induced effects leading to SDPs are presented. Then, SDPs due to the photo-induced inverse spin Hall effect and the circular photogalvanic effect, together with photocurrent due to the photon drag effect, are compared. This is followed by the main focus of nonlinear photocurrents in LHPs containing organic parts, starting from fundamentals related to spin-dependent optoelectronics. Finally, we conclude with a brief summary and future prospects.
Collapse
Affiliation(s)
| | | | | | | | - Lingfeng Chao
- Key Laboratory of Flexible Electronics (KLoFE) and Institute of Advanced Materials (IAM), School of Flexible Electronics (Future Technologies), Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China; (J.C.); (H.K.); (S.Z.); (K.W.)
| | - Mustafa Eginligil
- Key Laboratory of Flexible Electronics (KLoFE) and Institute of Advanced Materials (IAM), School of Flexible Electronics (Future Technologies), Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, China; (J.C.); (H.K.); (S.Z.); (K.W.)
| |
Collapse
|
22
|
Jeong J, Kiem DH, Guo D, Duan R, Watanabe K, Taniguchi T, Liu Z, Han MJ, Zheng S, Yang H. Spin-Selective Memtransistors with Magnetized Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310291. [PMID: 38235929 DOI: 10.1002/adma.202310291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 12/08/2023] [Indexed: 01/19/2024]
Abstract
Spin-polarized bands in pristine and proximity-induced magnetic materials are promising building blocks for future devices. Conceptually new memory, logic, and neuromorphic devices are conceived based on atomically thin magnetic materials and the manipulation of their spin-polarized bands via electrical and optical methods. A critical remaining issue is the direct probe and the optimized use of the magnetic coupling effect in van der Waals heterostructures, which requires further delicate design of atomically thin magnetic materials and devices. Here, a spin-selective memtransistor with magnetized single-layered graphene on a reactive antiferromagnetic material, CrI3, is reported. The spin-dependent hybridization between graphene and CrI3 atomic layers enables the spin-selective bandgap opening in the single-layered graphene and the electric field control of magnetization in a specific CrI3 layer. The microscopic working principle is clarified by the first-principles calculations and theoretical analysis of the transport data. Reliable memtransistor operations (i.e., memory and logic device-combined operations), as well as a spin-selective probe of Landau levels in the magnetized graphene, are achieved by using the subtle manipulation of the magnetic proximity effect via electrical means.
Collapse
Affiliation(s)
- Juyeong Jeong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Do Hoon Kiem
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Dan Guo
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Ruihuan Duan
- CINTRA CNRS/NTU/THALES, Research Techno Plaza, Nanyang Technological University, Singapore, 637371, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kenji Watanabe
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 3030044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 3030044, Japan
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Myung Joon Han
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Shoujun Zheng
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| |
Collapse
|
23
|
Xu Y, Zhang F, Fert A, Jaffres HY, Liu Y, Xu R, Jiang Y, Cheng H, Zhao W. Orbitronics: light-induced orbital currents in Ni studied by terahertz emission experiments. Nat Commun 2024; 15:2043. [PMID: 38448561 PMCID: PMC10917802 DOI: 10.1038/s41467-024-46405-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 02/26/2024] [Indexed: 03/08/2024] Open
Abstract
Orbitronics is based on the use of orbital currents as information carriers. Orbital currents can be generated from the conversion of charge or spin currents, and inversely, they could be converted back to charge or spin currents. Here we demonstrate that orbital currents can also be generated by femtosecond light pulses on Ni. In multilayers associating Ni with oxides and nonmagnetic metals such as Cu, we detect the orbital currents by their conversion into charge currents and the resulting terahertz emission. We show that the orbital currents extraordinarily predominate the light-induced spin currents in Ni-based systems, whereas only spin currents can be detected with CoFeB-based systems. In addition, the analysis of the time delays of the terahertz pulses leads to relevant information on the velocity and propagation length of orbital carriers. Our finding of light-induced orbital currents and our observation of their conversion into charge currents opens new avenues in orbitronics, including the development of orbitronic terahertz devices.
Collapse
Affiliation(s)
- Yong Xu
- National Key Lab of Spintronics, International Innovation Institute, Beihang University, Hangzhou, 311115, China
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Fan Zhang
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Albert Fert
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, 91767, France.
| | - Henri-Yves Jaffres
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, 91767, France
| | - Yongshan Liu
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Renyou Xu
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Yuhao Jiang
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Houyi Cheng
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China
| | - Weisheng Zhao
- National Key Lab of Spintronics, International Innovation Institute, Beihang University, Hangzhou, 311115, China.
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Hefei Innovation Research Institute, Beihang University, Hefei, 230013, China.
| |
Collapse
|
24
|
Merbouche H, Divinskiy B, Gouéré D, Lebrun R, El Kanj A, Cros V, Bortolotti P, Anane A, Demokritov SO, Demidov VE. True amplification of spin waves in magnonic nano-waveguides. Nat Commun 2024; 15:1560. [PMID: 38378662 PMCID: PMC10879122 DOI: 10.1038/s41467-024-45783-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Magnonic nano-devices exploit magnons - quanta of spin waves - to transmit and process information within a single integrated platform that has the potential to outperform traditional semiconductor-based electronics. The main missing cornerstone of this information nanotechnology is an efficient scheme for the amplification of propagating spin waves. The recent discovery of spin-orbit torque provided an elegant mechanism for propagation losses compensation. While partial compensation of the spin-wave losses has been achieved, true amplification - the exponential increase in the spin-wave intensity during propagation - has so far remained elusive. Here we evidence the operating conditions to achieve unambiguous amplification using clocked nanoseconds-long spin-orbit torque pulses in magnonic nano-waveguides, where the effective magnetization has been engineered to be close to zero to suppress the detrimental magnon scattering. We achieve an exponential increase in the intensity of propagating spin waves up to 500% at a propagation distance of several micrometers.
Collapse
Affiliation(s)
- H Merbouche
- Institute of Applied Physics, University of Muenster, Corrensstrasse 2-4, 48149, Muenster, Germany
| | - B Divinskiy
- Institute of Applied Physics, University of Muenster, Corrensstrasse 2-4, 48149, Muenster, Germany
| | - D Gouéré
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - R Lebrun
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - A El Kanj
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - V Cros
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - P Bortolotti
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - A Anane
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - S O Demokritov
- Institute of Applied Physics, University of Muenster, Corrensstrasse 2-4, 48149, Muenster, Germany
| | - V E Demidov
- Institute of Applied Physics, University of Muenster, Corrensstrasse 2-4, 48149, Muenster, Germany.
| |
Collapse
|
25
|
Cao Y, Ding H, Zuo Y, Li X, Zhao Y, Li T, Lei N, Cao J, Si M, Xi L, Jia C, Xue D, Yang D. Acoustic spin rotation in heavy-metal-ferromagnet bilayers. Nat Commun 2024; 15:1013. [PMID: 38307850 PMCID: PMC10837457 DOI: 10.1038/s41467-024-45317-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 01/19/2024] [Indexed: 02/04/2024] Open
Abstract
Through pumping a spin current from ferromagnet into heavy metal (HM) via magnetization precession, parts of the injected spins are in-plane rotated by the lattice vibration, namely acoustic spin rotation (ASR), which manifests itself as an inverse spin Hall voltage in HM with an additional 90° difference in angular dependency. When reversing the stacking order of bilayer with a counter-propagating spin current or using HMs with an opposite spin Hall angle, such ASR voltage shows the same sign, strongly suggesting that ASR changes the rotation direction due to interface spin-orbit interaction. With the drift-diffusion model of spin transport, we quantify the efficiency of ASR up to 30%. The finding of ASR endows the acoustic device with an ability to manipulate spin, and further reveals a new spin-orbit coupling between spin current and lattice vibration.
Collapse
Affiliation(s)
- Yang Cao
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Hao Ding
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Yalu Zuo
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Xiling Li
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Yibing Zhao
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Tong Li
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Na Lei
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jiangwei Cao
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Mingsu Si
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Li Xi
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Chenglong Jia
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Desheng Xue
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China.
| | - Dezheng Yang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China.
| |
Collapse
|
26
|
Zhang H, Liu Q, Deng L, Ma Y, Daneshmandi S, Cen C, Zhang C, Voyles PM, Jiang X, Zhao J, Chu CW, Gai Z, Li L. Room-Temperature Ferromagnetism in Epitaxial Bilayer FeSb/SrTiO 3(001) Terminated with a Kagome Lattice. NANO LETTERS 2024; 24:122-129. [PMID: 37913524 PMCID: PMC10786153 DOI: 10.1021/acs.nanolett.3c03415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/03/2023]
Abstract
Two-dimensional (2D) magnets exhibit unique physical properties for potential applications in spintronics. To date, most 2D ferromagnets are obtained by mechanical exfoliation of bulk materials with van der Waals interlayer interactions, and the synthesis of single- or few-layer 2D ferromagnets with strong interlayer coupling remains experimentally challenging. Here, we report the epitaxial growth of 2D non-van der Waals ferromagnetic bilayer FeSb on SrTiO3(001) substrates stabilized by strong coupling to the substrate, which exhibits in-plane magnetic anisotropy and a Curie temperature above 390 K. In situ low-temperature scanning tunneling microscopy/spectroscopy and density-functional theory calculations further reveal that an Fe Kagome layer terminates the bilayer FeSb. Our results open a new avenue for further exploring emergent quantum phenomena from the interplay of ferromagnetism and topology for application in spintronics.
Collapse
Affiliation(s)
- Huimin Zhang
- Department
of Physics and Astronomy, West Virginia
University, Morgantown, West Virginia 26506, United States
- State
Key Laboratory of Structural Analysis, Optimization and CAE Software
for Industrial Equipment, Dalian University
of Technology, Dalian, 116024, China
| | - Qinxi Liu
- Key
Laboratory of Materials Modification by Laser, Ion and Electron Beams
(Dalian University of Technology), Ministry
of Education, Dalian 116024, China
| | - Liangzi Deng
- Department
of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas, 77204, United States
| | - Yanjun Ma
- Department
of Physics and Astronomy, West Virginia
University, Morgantown, West Virginia 26506, United States
| | - Samira Daneshmandi
- Department
of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas, 77204, United States
| | - Cheng Cen
- Department
of Physics and Astronomy, West Virginia
University, Morgantown, West Virginia 26506, United States
- Beijing National
Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chenyu Zhang
- Department
of Materials Science and Engineering, University
of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Paul M. Voyles
- Department
of Materials Science and Engineering, University
of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Xue Jiang
- State
Key Laboratory of Structural Analysis, Optimization and CAE Software
for Industrial Equipment, Dalian University
of Technology, Dalian, 116024, China
- Key
Laboratory of Materials Modification by Laser, Ion and Electron Beams
(Dalian University of Technology), Ministry
of Education, Dalian 116024, China
| | - Jijun Zhao
- State
Key Laboratory of Structural Analysis, Optimization and CAE Software
for Industrial Equipment, Dalian University
of Technology, Dalian, 116024, China
- Key
Laboratory of Materials Modification by Laser, Ion and Electron Beams
(Dalian University of Technology), Ministry
of Education, Dalian 116024, China
| | - Ching-Wu Chu
- Department
of Physics and Texas Center for Superconductivity, University of Houston, Houston, Texas, 77204, United States
| | - Zheng Gai
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee, 37831 United States
| | - Lian Li
- Department
of Physics and Astronomy, West Virginia
University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
27
|
Kong JF, Ren Y, Tey MSN, Ho P, Khoo KH, Chen X, Soumyanarayanan A. Quantifying the Magnetic Interactions Governing Chiral Spin Textures Using Deep Neural Networks. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1025-1032. [PMID: 38156820 DOI: 10.1021/acsami.3c12655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The interplay of magnetic interactions in chiral multilayer films gives rise to nanoscale topological spin textures that form attractive elements for next-generation computing. Quantifying these interactions requires several specialized, time-consuming, and resource-intensive experimental techniques. Imaging of ambient domain configurations presents a promising avenue for high-throughput extraction of parent magnetic interactions. Here, we present a machine learning (ML)-based approach to simultaneously determine the key magnetic interactions─symmetric exchange, chiral exchange, and anisotropy─governing the chiral domain phenomenology in multilayers, using a single binarized image of domain configurations. Our convolutional neural network model, trained and validated on over 10,000 domain images, achieved R2 > 0.85 in predicting the parameters and independently learned the physical interdependencies between magnetic parameters. When applied to microscopy data acquired across samples, our model-predicted parameter trends are consistent with those of independent experimental measurements. These results establish ML-driven techniques as valuable, high-throughput complements to conventional determination of magnetic interactions and serve to accelerate materials and device development for nanoscale electronics.
Collapse
Affiliation(s)
- Jian Feng Kong
- Agency for Science, Technology & Research (A*STAR), Institute of High Performance Computing, Singapore 138632, Singapore
| | - Yuhua Ren
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - M S Nicholas Tey
- Agency for Science, Technology & Research (A*STAR), Institute of Materials Research & Engineering, Singapore 138634, Singapore
| | - Pin Ho
- Agency for Science, Technology & Research (A*STAR), Institute of Materials Research & Engineering, Singapore 138634, Singapore
| | - Khoong Hong Khoo
- Agency for Science, Technology & Research (A*STAR), Institute of High Performance Computing, Singapore 138632, Singapore
| | - Xiaoye Chen
- Agency for Science, Technology & Research (A*STAR), Institute of Materials Research & Engineering, Singapore 138634, Singapore
| | - Anjan Soumyanarayanan
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| |
Collapse
|
28
|
Yang MM, Zhu TY, Renz AB, Sun HM, Liu S, Gammon PM, Alexe M. Auxetic piezoelectric effect in heterostructures. NATURE MATERIALS 2024; 23:95-100. [PMID: 38036625 PMCID: PMC10769876 DOI: 10.1038/s41563-023-01736-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023]
Abstract
Inherent symmetry breaking at the interface has been fundamental to a myriad of physical effects and functionalities, such as efficient spin-charge interconversion, exotic magnetic structures and an emergent bulk photovoltaic effect. It has recently been demonstrated that interface asymmetry can induce sizable piezoelectric effects in heterostructures, even those consisting of centrosymmetric semiconductors, which provides flexibility to develop and optimize electromechanical coupling phenomena. Here, by targeted engineering of the interface symmetry, we achieve piezoelectric phenomena behaving as the electrical analogue of the negative Poisson's ratio. This effect, termed the auxetic piezoelectric effect, exhibits the same sign for the longitudinal (d33) and transverse (d31, d32) piezoelectric coefficients, enabling a simultaneous contraction or expansion in all directions under an external electrical stimulus. The signs of the transverse coefficients can be further tuned via in-plane symmetry anisotropy. The effects exist in a wide range of material systems and exhibit substantial coefficients, indicating potential implications for all-semiconductor actuator, sensor and filter applications.
Collapse
Affiliation(s)
- Ming-Min Yang
- Department of Physics, The University of Warwick, Coventry, UK.
- Hefei National Laboratory, Hefei, China.
- School of Emerging Technology, The University of Science and Technology of China, Hefei, China.
| | - Tian-Yuan Zhu
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, China
| | | | - He-Meng Sun
- Hefei National Laboratory, Hefei, China
- School of Emerging Technology, The University of Science and Technology of China, Hefei, China
| | - Shi Liu
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, China
| | | | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, UK.
| |
Collapse
|
29
|
Li J, Guo Z, Qin Y, Liu R, He Y, Zhu X, Xu F, He T. Rashba Effect and Spin-Dependent Excitonic Properties in Chiral Two-Dimensional/Three-Dimensional Composite Perovskite Films. J Phys Chem Lett 2023; 14:11697-11703. [PMID: 38109354 DOI: 10.1021/acs.jpclett.3c03247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Among various chiral semiconductor materials, chiral two-dimensional (2D)/three-dimensional (3D) composite perovskites (CPs) offer the benefits of strong interface asymmetry and energy transfer between 2D and 3D phases, making the chiral CPs promising for spintronic devices. Therefore, understanding their spintronic properties will be greatly important for expanding their relevant applications. In this work, we synthesized one pair of chiral 2D/3D CP films. Their Rashba effect and spin relaxation process have been investigated by polarization-dependent femtosecond transient absorption spectroscopy. Interestingly, under left- and right-handed circularly polarized light (CPL) excitation, a two-photon emission intensity difference is observed in chiral 2D/3D CP films at 298 K. This work sheds light on the spin-dependent excitonic characteristics of chiral 2D/3D CPs and confirms the feasibility of their application in near-infrared CPL detection.
Collapse
Affiliation(s)
- Junzi Li
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China
| | - Zhihang Guo
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Yan Qin
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Rulin Liu
- School of Science and Engineering, Chinese University of Hong Kong, Shenzhen, Shenzhen 518172, China
| | - Yejun He
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xi Zhu
- School of Science and Engineering, Chinese University of Hong Kong, Shenzhen, Shenzhen 518172, China
| | - Fuming Xu
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Tingchao He
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| |
Collapse
|
30
|
Liu W, Liu L, Cui B, Cheng S, Wu X, Cheng B, Miao T, Ren X, Chu R, Liu M, Zhao X, Wu S, Qin H, Hu J. Manipulation of Spin-Orbit Torque in Tungsten Oxide/Manganite Heterostructure by Ionic Liquid Gating and Orbit Engineering. ACS NANO 2023. [PMID: 37988035 DOI: 10.1021/acsnano.3c06686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Spin-orbit coupling (SOC) is the interaction between electron's spin and orbital motion, which could realize a charge-to-spin current conversion and enable an innovative method to switch the magnetization by spin-orbit torque (SOT). Varied techniques have been developed to manipulate and improve the SOT, but the role of the orbit degree of freedom, which should have a crucial bearing on the SOC and SOT, is still confusing. Here, we find that the charge-to-spin current conversion and SOT in W3O8-δ/(La, Sr)MnO3 could be produced or eliminated by ionic liquid gating. Through tuning the preferential occupancy of Mn/W-d electrons from the in-plane (dx2-y2) to out-of-plane (d3z2-r2) orbit, the SOT damping-like field efficiency is nearly doubled due to the enhanced spin Hall effect and interfacial Rashba-Edelstein effect. These findings not only offer intriguing opportunities to control the SOT for high-efficient spintronic devices but also could be a fundamental step toward spin-orbitronics in the future.
Collapse
Affiliation(s)
- Weikang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Liang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cui
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Shaobo Cheng
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450000, China
| | - Xinyi Wu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cheng
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Tingting Miao
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Xue Ren
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Ruiyue Chu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Min Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiangxiang Zhao
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Shuyun Wu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Hongwei Qin
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Jifan Hu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| |
Collapse
|
31
|
Sattigeri RM, Cuono G, Autieri C. Altermagnetic surface states: towards the observation and utilization of altermagnetism in thin films, interfaces and topological materials. NANOSCALE 2023; 15:16998-17005. [PMID: 37831060 DOI: 10.1039/d3nr03681b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The altermagnetism influences the electronic states allowing the presence of non-relativistic spin-splittings. Since altermagnetic spin-splitting is present along specific k-paths of the 3D Brillouin zone, we expect that the altermagnetic surface stateswill be present on specific surface orientations. We unveil the properties of the altermagnetic surface states considering three representative materials belonging to the orthorhombic, hexagonal and tetragonal space groups. We calculate the 2D projected Brillouin zone from the 3D Brillouin zone. We study the surfaces with their respective 2D Brillouin zones establishing where the spin-splittings with opposite sign merge annihilating the altermagnetic properties and on which surfaces the altermagnetism is preserved. Looking at the three principal surface orientations, we find that for several cases two surfaces are blind to the altermagnetism, while the altermagnetism survives for one surface orientation. Which surface preserves the altermagnetism depends also on themagnetic order. We qualitatively show that an electric field orthogonal to the blind surface can activate the altermagnetism. Our projection method was proven for strong altermagnetism, but it will be equivalently valid for recently discovered weak altermagnetism. Our results predict which surfaces to cleave in order to preserve altermagnetism in surfaces or interfaces and this paves the way to observe non-relativistic altermagnetic spin-splitting in thin films via spin-resolved ARPES and to interface the altermagnetism with other collective modes. We open future perspectives for the study of altermagnetic effects on the trivial and topological surface states.
Collapse
Affiliation(s)
- Raghottam M Sattigeri
- International Research Centre Magtop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland.
| | - Giuseppe Cuono
- International Research Centre Magtop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland.
| | - Carmine Autieri
- International Research Centre Magtop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland.
| |
Collapse
|
32
|
Longo E, Locatelli L, Tsipas P, Lintzeris A, Dimoulas A, Fanciulli M, Longo M, Mantovan R. Exploiting the Close-to-Dirac Point Shift of the Fermi Level in the Sb 2Te 3/Bi 2Te 3 Topological Insulator Heterostructure for Spin-Charge Conversion. ACS APPLIED MATERIALS & INTERFACES 2023; 15:50237-50245. [PMID: 37862590 PMCID: PMC10623560 DOI: 10.1021/acsami.3c08830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/22/2023]
Abstract
Properly tuning the Fermi level position in topological insulators is of vital importance to tailor their spin-polarized electronic transport and to improve the efficiency of any functional device based on them. Here, we report the full in situ metal organic chemical vapor deposition (MOCVD) and study of a highly crystalline Bi2Te3/Sb2Te3 topological insulator heterostructure on top of large area (4″) Si(111) substrates. The bottom Sb2Te3 layer serves as an ideal seed layer for the growth of highly crystalline Bi2Te3 on top, also inducing a remarkable shift of the Fermi level to place it very close to the Dirac point, as visualized by angle-resolved photoemission spectroscopy. To exploit such ideal topologically protected surface states, we fabricate the simple spin-charge converter Si(111)/Sb2Te3/Bi2Te3/Au/Co/Au and probe the spin-charge conversion (SCC) by spin pumping ferromagnetic resonance. A large SCC is measured at room temperature and is interpreted within the inverse Edelstein effect, thus resulting in a conversion efficiency of λIEEE ∼ 0.44 nm. Our results demonstrate the successful tuning of the surface Fermi level of Bi2Te3 when grown on top of Sb2Te3 with a full in situ MOCVD process, which is highly interesting in view of its future technology transfer.
Collapse
Affiliation(s)
- Emanuele Longo
- CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, Agrate
Brianza 20864, Italy
| | - Lorenzo Locatelli
- CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, Agrate
Brianza 20864, Italy
| | - Polychronis Tsipas
- National
Centre for Scientific Research “Demokritos”, Institute of Nanoscience and Nanotechnology, Agia Paraskevi 15341, Athens, Greece
| | - Akylas Lintzeris
- National
Centre for Scientific Research “Demokritos”, Institute of Nanoscience and Nanotechnology, Agia Paraskevi 15341, Athens, Greece
- Department
of Physics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Athens 10682, Greece
| | - Athanasios Dimoulas
- National
Centre for Scientific Research “Demokritos”, Institute of Nanoscience and Nanotechnology, Agia Paraskevi 15341, Athens, Greece
| | - Marco Fanciulli
- Department
of Material Science, University of Milano
Bicocca, Via R. Cozzi 55, Milan 20125, Italy
| | - Massimo Longo
- CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, Agrate
Brianza 20864, Italy
- Department
of Chemical Science and Technologies, University
of Rome Tor Vergata, Via della Ricerca Scientifica, Rome 100133, Italy
| | - Roberto Mantovan
- CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, Agrate
Brianza 20864, Italy
| |
Collapse
|
33
|
Du Y, Zhao Y, Wang L, He Z, Wu Y, Wang C, Zhao L, Jiang Z, Liu M, Zhou Z. Deterministic Magnetization Reversal in Synthetic Antiferromagnets using Natural Light. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302884. [PMID: 37403297 DOI: 10.1002/smll.202302884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/31/2023] [Indexed: 07/06/2023]
Abstract
Traditional current-driven spintronics is limited by localized heating issues and large energy consumption, restricting their data storage density and operation speed. Meanwhile, voltage-driven spintronics with much lower energy dissipation also suffers from charge-induced interfacial corrosion. Thereby finding a novel way of tuning ferromagnetism is crucial for spintronics with energy-saving and good reliability. Here, a visible light tuning of interfacial exchange interaction via photoelectron doping into synthetic antiferromagnetic heterostructure of CoFeB/Cu/CoFeB/PN Si substrate is demonstrated. Then, a complete, reversible magnetism switching between antiferromagnetic (AFM) and ferromagnetic (FM) states with visible light on and off is realized. Moreover, a visible light control of 180° deterministic magnetization switching with a tiny magnetic bias field is achieved. The magnetic optical Kerr effect results further reveal the magnetic domain switching pathway between AFM and FM domains. The first-principle calculations conclude that the photoelectrons fill in the unoccupied band and raise the Fermi energy, which increases the exchange interaction. Lastly, a prototype device with visible light control of two states switching with a 0.35% giant magnetoresistance ratio change (maximal 0.4%), paving the way toward fast, compact, and energy-efficient solar-driven memories is fabricated.
Collapse
Affiliation(s)
- Yujing Du
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Yifan Zhao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Lei Wang
- Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, No. 28 Xianning West Road Xi'an, Shaanxi, 710049, China
| | - Zhexi He
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Yangyang Wu
- School of Mathematical Sciences, Tiangong University, Tianjin, 300387, China
| | - Chenying Wang
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Libo Zhao
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ming Liu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ziyao Zhou
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| |
Collapse
|
34
|
Zhang J, Zhao Y, Dou P, Peng W, Huang H, Deng X, Wang Y, Liu J, Xu J, Zhu T, Qi J, Zheng X, Wu Y, Shen B, Wang S. Controllable Spin-Orbit Torque Induced by Interfacial Ion Absorption in Ta/CoFeB/MgO Multilayers with Canted Magnetizations. ACS APPLIED MATERIALS & INTERFACES 2023; 15:49902-49910. [PMID: 37815887 DOI: 10.1021/acsami.3c12551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
Electrically generated spin-orbit torque (SOT) has emerged as a powerful pathway to control magnetization for spintronic applications including memory, logic, and neurocomputing. However, the requirement of external magnetic fields, together with the ultrahigh current density, is the main obstacle for practical SOT devices. In this paper, we report that the field-free SOT-driven magnetization switching can be successfully realized by interfacial ion absorption in perpendicular Ta/CoFeB/MgO multilayers. Besides, the tunable SOT efficiency exhibits a strong dependence on interfacial Ti insertion thicknesses. Polarized neutron reflection measurements demonstrate the existence of canted magnetization with Ti inserted, which leads to deterministic magnetization switching. In addition, interfacial characterization and first-principles calculations reveal that B absorption by the Ti layer is the main cause behind the enhanced interfacial transparency, which determines the tunable SOT efficiency. Our findings highlight an attractive scheme to a purely electric control spin configuration, enabling innovative designs for SOT-based spintronics via interfacial engineering.
Collapse
Affiliation(s)
- Jingyan Zhang
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yunchi Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Pengwei Dou
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Wenlin Peng
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - He Huang
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiao Deng
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuanbo Wang
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Jialong Liu
- Department of Physics and Electronics, School of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jiawang Xu
- Anhui Key Laboratory of Magnetic Functional Materials and Devices, School of Materials Science and Engineering, Anhui University, Hefei 230601, China
| | - Tao Zhu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Qi
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xinqi Zheng
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanfei Wu
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shouguo Wang
- School of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Anhui Key Laboratory of Magnetic Functional Materials and Devices, School of Materials Science and Engineering, Anhui University, Hefei 230601, China
| |
Collapse
|
35
|
Alhyder R, Cappellaro A, Lemeshko M, Volosniev AG. Achiral dipoles on a ferromagnet can affect its magnetization direction. J Chem Phys 2023; 159:104103. [PMID: 37694742 DOI: 10.1063/5.0165806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/22/2023] [Indexed: 09/12/2023] Open
Abstract
We demonstrate the possibility of a coupling between the magnetization direction of a ferromagnet and the tilting angle of adsorbed achiral molecules. To illustrate the mechanism of the coupling, we analyze a minimal Stoner model that includes Rashba spin-orbit coupling due to the electric field on the surface of the ferromagnet. The proposed mechanism allows us to study magnetic anisotropy of the system with an extended Stoner-Wohlfarth model and argue that adsorbed achiral molecules can change magnetocrystalline anisotropy of the substrate. Our research aims to motivate further experimental studies of the current-free chirality induced spin selectivity effect involving both enantiomers.
Collapse
Affiliation(s)
- Ragheed Alhyder
- Institute of Science and Technology Austria (ISTA), Am Campus 1, Klosterneuburg 3400, Austria
| | - Alberto Cappellaro
- Institute of Science and Technology Austria (ISTA), Am Campus 1, Klosterneuburg 3400, Austria
| | - Mikhail Lemeshko
- Institute of Science and Technology Austria (ISTA), Am Campus 1, Klosterneuburg 3400, Austria
| | - Artem G Volosniev
- Institute of Science and Technology Austria (ISTA), Am Campus 1, Klosterneuburg 3400, Austria
| |
Collapse
|
36
|
Castell-Queralt J, Abad-López G, González-Gómez L, Del-Valle N, Navau C. Survival of skyrmions along granular racetracks at room temperature. NANOSCALE ADVANCES 2023; 5:4728-4734. [PMID: 37705781 PMCID: PMC10496888 DOI: 10.1039/d3na00464c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 07/27/2023] [Indexed: 09/15/2023]
Abstract
Skyrmions can be envisioned as bits of information that can be transported along nanoracetracks. However, temperature, defects, and/or granularity can produce diffusion, pinning, and, in general, modification in their dynamics. These effects may cause undesired errors in information transport. We present simulations of a realistic system where both the (room) temperature and sample granularity are taken into account. Key feasibility magnitudes, such as the success probability of a skyrmion traveling a given distance along the racetrack, are calculated. The results are evaluated in terms of the eventual loss of skyrmions by pinning, destruction at the edges, or excessive delay due to granularity. The model proposed is based on the Fokker-Planck equation resulting from Thiele's rigid model for skyrmions. The results could serve to establish error detection criteria and, in general, to discern the dynamics of skyrmions in realistic situations.
Collapse
Affiliation(s)
- Josep Castell-Queralt
- Departament de Física, Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Catalonia Spain
| | - Guillermo Abad-López
- Departament de Física, Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Catalonia Spain
| | - Leonardo González-Gómez
- Departament de Física, Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Catalonia Spain
| | - Nuria Del-Valle
- Departament de Física, Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Catalonia Spain
| | - Carles Navau
- Departament de Física, Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Catalonia Spain
| |
Collapse
|
37
|
Fu W, Tan L, Wang PP. Chiral Inorganic Nanomaterials for Photo(electro)catalytic Conversion. ACS NANO 2023; 17:16326-16347. [PMID: 37540624 DOI: 10.1021/acsnano.3c04337] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/06/2023]
Abstract
Chiral inorganic nanomaterials due to their unique asymmetric nanostructures have gradually demonstrated intriguing chirality-dependent performance in photo(electro)catalytic conversion, such as water splitting. However, understanding the correlation between chiral inorganic characteristics and the photo(electro)catalytic process remains challenging. In this perspective, we first highlight the chirality source of inorganic nanomaterials and briefly introduce photo(electro)catalysis systems. Then, we delve into an in-depth discussion of chiral effects exerted by chiral nanostructures and their photo-electrochemistry properties, while emphasizing the emerging chiral inorganic nanomaterials for photo(electro)catalytic conversion. Finally, the challenges and opportunities of chiral inorganic nanomaterials for photo(electro)catalytic conversion are prospected. This perspective provides a comprehensive overview of chiral inorganic nanomaterials and their potential in photo(electro)catalytic conversion, which is beneficial for further research in this area.
Collapse
Affiliation(s)
- Wenlong Fu
- State Key Laboratory for Mechanical Behavior of Materials, Shaanxi International Research Center for Soft Matter, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Lili Tan
- State Key Laboratory for Mechanical Behavior of Materials, Shaanxi International Research Center for Soft Matter, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Peng-Peng Wang
- State Key Laboratory for Mechanical Behavior of Materials, Shaanxi International Research Center for Soft Matter, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| |
Collapse
|
38
|
García-Blázquez MA, Dednam W, Palacios JJ. Nonequilibrium Magneto-Conductance as a Manifestation of Spin Filtering in Chiral Nanojunctions. J Phys Chem Lett 2023; 14:7931-7939. [PMID: 37646507 PMCID: PMC10494227 DOI: 10.1021/acs.jpclett.3c01922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/10/2023] [Indexed: 09/01/2023]
Abstract
It is generally accepted that spin-dependent electron transmission may appear in chiral systems, even without magnetic components, as long as significant spin-orbit coupling is present in some of its elements. However, how this chirality-induced spin selectivity (CISS) manifests in experiments, where the system is taken out of equilibrium, is still debated. Aided by group theoretical considerations and nonequilibrium DFT-based quantum transport calculations, here we show that when spatial symmetries that forbid a finite spin polarization in equilibrium are broken, a net spin accumulation appears at finite bias in an arbitrary two-terminal nanojunction. Furthermore, when a suitably magnetized detector is introduced into the system, the net spin accumulation, in turn, translates into a finite magneto-conductance. The symmetry prerequisites are mostly analogous to those for the spin polarization at any bias with the vectorial nature given by the direction of magnetization, hence establishing an interconnection between these quantities.
Collapse
Affiliation(s)
- M. A. García-Blázquez
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - W. Dednam
- Department
of Physics, Science Campus, University of
South Africa, Florida
Park, Johannesburg 1710, South Africa
| | - J. J. Palacios
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| |
Collapse
|
39
|
Choi EM, Kim T, Cho BW, Lee YH. Proximity-Induced Tunable Magnetic Order at the Interface of All-van der Waals-Layered Heterostructures. ACS NANO 2023; 17:15656-15665. [PMID: 37523780 DOI: 10.1021/acsnano.3c02764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Spin-orbit coupling (SOC) plays a crucial role in controlling the spin-charge conversion efficiency, spin torque, and complex magnetic spin structures. In this study, we investigate the interplay between SOC and ferromagnetism in heterostructures of large-SOC and magnetic materials. We highlight the importance of the SOC-proximity effect on magnetic ordering in all-van der Waals-layered heterostructures, specifically Fe3GeTe2(FGT)/monolayer W1-xVxSe2 (x = 0 and 0.05). By increasing the SOC strength, we demonstrate various magnetic orderings induced at the interface of the heterostructure, including spin-flop, spin-flip, and inverted magnetization. Moreover, we show a sharp magnetic switching from antiferromagnetic state to ferromagnetic state in FGT/W0.95V0.05Se2, which is characteristic of the synthetic antiferromagnetic structure. This proof-of-concept result offers the possibility of interface-tailoring spintronics, including two-dimensional magnetoresistive random access memory toggle switching. Our findings provide insight into the design and development of next-generation spintronic devices by exploiting the interplay between SOC and magnetic ordering in all-van der Waals-layered heterostructures.
Collapse
Affiliation(s)
- Eun-Mi Choi
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Taesoo Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Byeong Wook Cho
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Sungkyunkwan University, Suwon 16419, Republic of Korea
- Advanced Facility Center for Quantum Technology, Sungkyunkwan University, Suwon 16419, Republic of Korea
| |
Collapse
|
40
|
Sahu P, Yang Y, Fan Y, Jaffrès H, Chen JY, Devaux X, Fagot-Revurat Y, Migot S, Rongione E, Chen T, Abel Dainone P, George JM, Dhillon S, Micica M, Lu Y, Wang JP. Room Temperature Spin-to-Charge Conversion in Amorphous Topological Insulating Gd-Alloyed Bi xSe 1-x/CoFeB Bilayers. ACS APPLIED MATERIALS & INTERFACES 2023; 15:38592-38602. [PMID: 37550946 DOI: 10.1021/acsami.3c07695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Disordered topological insulator (TI) films have gained intense interest by benefiting from both the TI's exotic transport properties and the advantage of mass production by sputtering. Here, we report on the clear evidence of spin-charge conversion (SCC) in amorphous Gd-alloyed BixSe1-x (BSG)/CoFeB bilayers fabricated by sputtering, which could be related to the amorphous TI surface states. Two methods have been employed to study SCC in BSG (tBSG = 6-16 nm)/CoFeB(5 nm) bilayers with different BSG thicknesses. First, spin pumping is used to generate a spin current in CoFeB and detect SCC by the inverse Edelstein effect (IEE). The maximum SCC efficiency (SCE) is measured to be as large as 0.035 nm (IEE length λIEE) in a 6 nm thick BSG sample, which shows a strong decay when tBSG increases due to the increase of BSG surface roughness. The second method is THz time-domain spectroscopy, which reveals a small tBSG dependence of SCE, validating the occurrence of a pure interface state-related SCC. Furthermore, our angle-resolved photoemission spectroscopy data show dispersive two-dimensional surface states that cross the bulk gap until the Fermi level, strengthening the possibility of SCC due to the amorphous TI states. Our studies provide a new experimental direction toward the search for topological systems in amorphous solids.
Collapse
Affiliation(s)
- Protyush Sahu
- School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, Minnesota 55455, United States
| | - Yifei Yang
- Department of Electrical and Computer Engineering, University of Minnesota, 200 Union Street SE, Minneapolis, Minnesota 55455, United States
| | - Yihong Fan
- Department of Electrical and Computer Engineering, University of Minnesota, 200 Union Street SE, Minneapolis, Minnesota 55455, United States
| | - Henri Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Jun-Yang Chen
- Department of Electrical and Computer Engineering, University of Minnesota, 200 Union Street SE, Minneapolis, Minnesota 55455, United States
| | - Xavier Devaux
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Yannick Fagot-Revurat
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Sylvie Migot
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Enzo Rongione
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005 Paris, France
| | - Tongxin Chen
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Pambiang Abel Dainone
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Jean-Marie George
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Sukhdeep Dhillon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005 Paris, France
| | - Martin Micica
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005 Paris, France
| | - Yuan Lu
- Institut Jean Lamour, Université de Lorraine, CNRS, UMR 7198, Campus ARTEM, 2 Allée André Guinier, 54011 Nancy, France
| | - Jian-Ping Wang
- School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, Minnesota 55455, United States
- Department of Electrical and Computer Engineering, University of Minnesota, 200 Union Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
41
|
Krishnia S, Sassi Y, Ajejas F, Sebe N, Reyren N, Collin S, Denneulin T, Kovács A, Dunin-Borkowski RE, Fert A, George JM, Cros V, Jaffrès H. Large Interfacial Rashba Interaction Generating Strong Spin-Orbit Torques in Atomically Thin Metallic Heterostructures. NANO LETTERS 2023; 23:6785-6791. [PMID: 37524333 PMCID: PMC10416352 DOI: 10.1021/acs.nanolett.2c05091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 06/22/2023] [Indexed: 08/02/2023]
Abstract
The hallmark of spintronics has been the ability of spin-orbit interactions to convert a charge current into a spin current and vice versa, mainly in the bulk of heavy metal thin films. Here, we demonstrate how a light metal interface profoundly affects both the nature of spin-orbit torques and its efficiency in terms of damping-like (HDL) and field-like (HFL) effective fields in ultrathin Co films. We measure unexpectedly HFL/HDL ratios much larger than 1 by inserting a nanometer-thin Al metallic layer in Pt|Co|Al|Pt as compared to a similar stacking, including Cu as a reference. From our modeling, these results evidence the existence of large Rashba interaction at the Co|Al interface generating a giant HFL, which is not expected from a metallic interface. The occurrence of such enhanced torques from an interfacial origin is further validated by demonstrating current-induced magnetization reversal showing a significant decrease of the critical current for switching.
Collapse
Affiliation(s)
- Sachin Krishnia
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Yanis Sassi
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Fernando Ajejas
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Nicolas Sebe
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Nicolas Reyren
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Sophie Collin
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Thibaud Denneulin
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C
1) and Peter Grünberg Institut (PGI-5), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - András Kovács
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C
1) and Peter Grünberg Institut (PGI-5), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Rafal E. Dunin-Borkowski
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C
1) and Peter Grünberg Institut (PGI-5), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Albert Fert
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Jean-Marie George
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Vincent Cros
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Henri Jaffrès
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| |
Collapse
|
42
|
Li H, Wang L, Song Y, Wu Y, Zhang H, Du A, He X. Understanding the Insight Mechanism of Chemical-Mechanical Degradation of Layered Co-Free Ni-Rich Cathode Materials: A Review. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302208. [PMID: 37154228 DOI: 10.1002/smll.202302208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/20/2023] [Indexed: 05/10/2023]
Abstract
Layered Cobalt (Co)-free Nickel (Ni)-rich cathode materials have attracted much attention due to their high energy density and low cost. Still, their further development is hampered by material instability caused by the chemical/mechanical degradation of the material. Although there are numerous doping and modification approaches to improve the stability of layered cathode materials, these approaches are still in the laboratory stage and require further research before commercial application. To fully exploit the potential of layered cathode materials, a more comprehensive theoretical understanding of the underlying issues is necessary, along with active exploration of previously unrevealed mechanisms. This paper presents the phase transition mechanism of Co-free Ni-rich cathode materials, the existing problems, and the state-of-the-art characterization tools employed to study the phase transition. The causes of crystal structure degradation, interfacial instability, and mechanical degradation are elaborated, from the material's crystal structure to its phase transition and atomic orbital splitting. By organizing and summarizing these mechanisms, this paper aims to establish connections among common research problems and to identify future research priorities, thereby facilitating the rapid development of Co-free Ni-rich materials.
Collapse
Affiliation(s)
- Hang Li
- School of Automotive Studies, Tongji University, Shanghai, 201804, China
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Li Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Youzhi Song
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Yingqiang Wu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Hao Zhang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| | - Aimin Du
- School of Automotive Studies, Tongji University, Shanghai, 201804, China
| | - Xiangming He
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
43
|
Zheng N, Liu H, Zeng YJ. Dynamical Behavior of Pure Spin Current in Organic Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207506. [PMID: 36995070 DOI: 10.1002/advs.202207506] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/27/2023] [Indexed: 06/04/2023]
Abstract
Growing concentration on the novel information processing technology and low-cost, flexible materials make the spintronics and organic materials appealing for the future interdisciplinary investigations. Organic spintronics, in this context, has arisen and witnessed great advances during the past two decades owing to the continuous innovative exploitation of the charge-contained spin polarized current. Albeit with such inspiring facts, charge-absent spin angular momentum flow, namely pure spin currents (PSCs) are less probed in organic functional solids. In this review, the past exploring journey of PSC phenomenon in organic materials are retrospected, including non-magnetic semiconductors and molecular magnets. Starting with the basic concepts and the generation mechanism for PSC, the representative experimental observations of PSC in the organic-based networks are subsequently demonstrated and summarized, by accompanying explicit discussion over the propagating mechanism of net spin itself in the organic media. Finally, future perspectives on PSC in organic materials are illustrated mainly from the material point of view, including single molecule magnets, complexes for the organic ligands framework as well as the lanthanide metal complexes, organic radicals, and the emerging 2D organic magnets.
Collapse
Affiliation(s)
- Naihang Zheng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology in Shenzhen, 518055, Shenzhen, P. R. China
| | - Haoliang Liu
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology in Shenzhen, 518055, Shenzhen, P. R. China
| | - Yu-Jia Zeng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| |
Collapse
|
44
|
Carvalho PC, Miranda IP, Brandão J, Bergman A, Cezar JC, Klautau AB, Petrilli HM. Correlation of Interface Interdiffusion and Skyrmionic Phases. NANO LETTERS 2023. [PMID: 37235539 DOI: 10.1021/acs.nanolett.3c00428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Magnetic skyrmions are prime candidates for the next generation of spintronic devices. Skyrmions and other topological magnetic structures are known to be stabilized by the Dzyaloshinskii-Moriya interaction (DMI) that occurs when the inversion symmetry is broken in thin films. Here, we show by first-principles calculations and atomistic spin dynamics simulations that metastable skyrmionic states can also be found in nominally symmetric multilayered systems. We demonstrate that this is correlated with the large enhancement of the DMI strength due to the presence of local defects. In particular, we find that metastable skyrmions can occur in Pd/Co/Pd multilayers without external magnetic fields and can be stable even near room temperature conditions. Our theoretical findings corroborate with magnetic force microscopy images and X-ray magnetic circular dichroism measurements and highlight the possibility of tuning the intensity of DMI by using interdiffusion at thin film interfaces.
Collapse
Affiliation(s)
- Pamela C Carvalho
- Universidade de São Paulo, Instituto de Física, Rua do Matão, 1371, São Paulo 05508-090, São Paulo, Brazil
| | - Ivan P Miranda
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala 75120, Sweden
| | - Jeovani Brandão
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, Campinas 13083-970, São Paulo, Brazil
| | - Anders Bergman
- Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala 75120, Sweden
| | - Júlio C Cezar
- Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, Campinas 13083-970, São Paulo, Brazil
| | - Angela B Klautau
- Faculdade de Física, Universidade Federal do Pará, Belém 66075-110 , Pará, Brazil
- Departamento de Física da Universidade de Aveiro, Aveiro 3810-183, Portugal
| | - Helena M Petrilli
- Universidade de São Paulo, Instituto de Física, Rua do Matão, 1371, São Paulo 05508-090, São Paulo, Brazil
| |
Collapse
|
45
|
Yang H, Ormaza M, Chi Z, Dolan E, Ingla-Aynés J, Safeer CK, Herling F, Ontoso N, Gobbi M, Martín-García B, Schiller F, Hueso LE, Casanova F. Gate-Tunable Spin Hall Effect in an All-Light-Element Heterostructure: Graphene with Copper Oxide. NANO LETTERS 2023; 23:4406-4414. [PMID: 37140909 DOI: 10.1021/acs.nanolett.3c00687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Graphene is a light material for long-distance spin transport due to its low spin-orbit coupling, which at the same time is the main drawback for exhibiting a sizable spin Hall effect. Decoration by light atoms has been predicted to enhance the spin Hall angle in graphene while retaining a long spin diffusion length. Here, we combine a light metal oxide (oxidized Cu) with graphene to induce the spin Hall effect. Its efficiency, given by the product of the spin Hall angle and the spin diffusion length, can be tuned with the Fermi level position, exhibiting a maximum (1.8 ± 0.6 nm at 100 K) around the charge neutrality point. This all-light-element heterostructure shows a larger efficiency than conventional spin Hall materials. The gate-tunable spin Hall effect is observed up to room temperature. Our experimental demonstration provides an efficient spin-to-charge conversion system free from heavy metals and compatible with large-scale fabrication.
Collapse
Affiliation(s)
- Haozhe Yang
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Maider Ormaza
- Departamento de Polímeros y Materiales Avanzados: Física Química y Tecnología Facultad de Químicas, UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
| | - Zhendong Chi
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Eoin Dolan
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Josep Ingla-Aynés
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - C K Safeer
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Franz Herling
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Nerea Ontoso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Marco Gobbi
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
- Centro de Física de Materiales (CSIC-EHU/UPV) and Materials Physics Center (MPC), 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Beatriz Martín-García
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
| | - Frederik Schiller
- Centro de Física de Materiales (CSIC-EHU/UPV) and Materials Physics Center (MPC), 20018 Donostia-San Sebastian, Basque Country, Spain
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Luis E Hueso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
| |
Collapse
|
46
|
Wang H, Wen Y, Zhao X, Cheng R, Yin L, Zhai B, Jiang J, Li Z, Liu C, Wu F, He J. Heteroepitaxy of 2D CuCr 2 Te 4 with Robust Room-temperature Ferromagnetism. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211388. [PMID: 36780341 DOI: 10.1002/adma.202211388] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/21/2023] [Indexed: 05/05/2023]
Abstract
Magnetic materials in 2D have attracted widespread attention for their intriguing magnetic properties. 2D magnetic heterostructures can provide unprecedented opportunities for exploring fundamental physics and novel spintronic devices. Here, the heteroepitaxial growth of ferromagnetic CuCr2 Te4 nanosheets is reported on Cr2 Te3 and mica by chemical vapor deposition. Magneto-optical Kerr effect measurements reveal the thickness-dependent ferromagnetism of CuCr2 Te4 nanosheets on mica, where a decrease of Curie temperature (TC ) from 320 to 260 K and an enhancement of perpendicular magnetic anisotropy with reducing thickness are observed. Moreover, lattice-matched heteroepitaxial ultrathin CuCr2 Te4 on Cr2 Te3 exhibits an enhanced robust ferromagnetism with TC up to 340 K due to the interfacial charge transfer. Stripe-type magnetic domains and single magnetic domain are discovered in this heterostructure with different thicknesses. The work provides a way to construct robust room-temperature 2D magnetic heterostructures for functional spintronic devices.
Collapse
Affiliation(s)
- Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Baoxing Zhai
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Jian Jiang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Zhongwei Li
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Chuansheng Liu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Fengcheng Wu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, P. R. China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, P. R. China
- International College, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Hubei Luojia Laboratory, Wuhan, 430072, P. R. China
| |
Collapse
|
47
|
Xu T, Zhang Y, Wang Z, Bai H, Song C, Liu J, Zhou Y, Je SG, N'Diaye AT, Im MY, Yu R, Chen Z, Jiang W. Systematic Control of Ferrimagnetic Skyrmions via Composition Modulation in Pt/Fe 1-xTb x/Ta Multilayers. ACS NANO 2023; 17:7920-7928. [PMID: 37010987 DOI: 10.1021/acsnano.3c02006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Magnetic skyrmions are topological spin textures that can be used as memory and logic components for advancing the next generation spintronics. In this regard, control of nanoscale skyrmions, including their sizes and densities, is of particular importance for enhancing the storage capacity of skyrmionic devices. Here, we propose a viable route for engineering ferrimagnetic skyrmions via tuning the magnetic properties of the involved ferrimagnets Fe1-xTbx. Via tuning the composition of Fe1-xTbx that alters the magnetic anisotropy and the saturation magnetization, the size of the ferrimagnetic skyrmion (ds) and the average density (ηs) can be effectively tailored in [Pt/Fe1-xTbx/Ta]10 multilayers. In particular, a stabilization of sub-50 nm skyrmions with a high density is demonstrated at room temperature. Our work provides an effective approach for designing ferrimagnetic skyrmions with the desired size and density, which could be useful for enabling high-density ferrimagnetic skyrmionics.
Collapse
Affiliation(s)
- Teng Xu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Yuxuan Zhang
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Zidong Wang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Hao Bai
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Chengkun Song
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Jiahao Liu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Soong-Geun Je
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Alpha T N'Diaye
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Mi-Young Im
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Rong Yu
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Zhen Chen
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Wanjun Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| |
Collapse
|
48
|
Gan Y, Yang F, Kong L, Chen X, Xu H, Zhao J, Li G, Zhao Y, Yan L, Zhong Z, Chen Y, Ding H. Light-Induced Giant Rashba Spin-Orbit Coupling at Superconducting KTaO 3 (110) Heterointerfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2300582. [PMID: 36972144 DOI: 10.1002/adma.202300582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/07/2023] [Indexed: 05/16/2023]
Abstract
The 2D electron system (2DES) at the KTaO3 surface or heterointerface with 5d orbitals hosts extraordinary physical properties, including a stronger Rashba spin-orbit coupling (RSOC), higher superconducting transition temperature, and potential of topological superconductivity. Herein, a huge enhancement of RSOC under light illumination achieved at a superconducting amorphous-Hf0.5 Zr0.5 O2 /KTaO3 (110) heterointerfaces is reported. The superconducting transition is observed with Tc = 0.62 K and the temperature-dependent upper critical field reveals the interaction between spin-orbit scattering and superconductivity. A strong RSOC with Bso = 1.9 T is revealed by weak antilocalization in the normal state, which undergoes sevenfold enhancement under light illumination. Furthermore, RSOC strength develops a dome-shaped dependence of carrier density with the maximum of Bso = 12.6 T achieved near the Lifshitz transition point nc ≈ 4.1 × 1013 cm-2 . The highly tunable giant RSOC at KTaO3 (110)-based superconducting interfaces show great potential for spintronics.
Collapse
Affiliation(s)
- Yulin Gan
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Fazhi Yang
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lingyuan Kong
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xuejiao Chen
- Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo, 315201, China
| | - Hao Xu
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jin Zhao
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Gang Li
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuchen Zhao
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lei Yan
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhicheng Zhong
- Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo, 315201, China
| | - Yunzhong Chen
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hong Ding
- Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China
| |
Collapse
|
49
|
Bhattacharya S, Datta S. Evidence of linear and cubic Rashba effect in non-magnetic heterostructure. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:205501. [PMID: 36848680 DOI: 10.1088/1361-648x/acbf94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
TheLaAlO3/KTaO3system serves as a prototype to study the electronic properties that emerge as a result of spin-orbit coupling (SOC). In this article, we have used first-principles calculations to systematically study two types of defect-free (0 0 1) interfaces, which are termed as Type-I and Type-II. While the Type-I heterostructure produces a two dimensional (2D) electron gas, the Type-II heterostructure hosts an oxygen-rich 2D hole gas at the interface. Furthermore, in the presence of intrinsic SOC, we have found evidence of both cubic and linear Rashba interactions in the conduction bands of the Type-I heterostructure. On the contrary, there is spin-splitting of both the valence and the conduction bands in the Type-II interface, which are found to be only linear Rashba type. Interestingly, the Type-II interface also harbors a potential photocurrent transition path, making it an excellent platform to study the circularly polarized photogalvanic effect.
Collapse
Affiliation(s)
- Sanchari Bhattacharya
- Department of Physics and Astronomy, National Institute of Technology, Rourkela, 769008 Odisha, India
| | - Sanjoy Datta
- Department of Physics and Astronomy, National Institute of Technology, Rourkela, 769008 Odisha, India
- Center for Nanomaterials, National Institute of Technology, Rourkela, 769008 Odisha, India
| |
Collapse
|
50
|
Wang W, Sun R, Shen W, Jia Z, Deepak FL, Zhang Y, Wang Z. Atomic structure and large magnetic anisotropy in air-sensitive layered ferromagnetic VI 3. NANOSCALE 2023; 15:4628-4635. [PMID: 36779225 DOI: 10.1039/d2nr06531b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We report the air-sensitivity, atomic structure, and magnetic anisotropy of VI3 single crystals. We find that VI3 nanocrystals exhibit a large MR/MS ratio of around 0.75 and a uniaxial anisotropic constant of an order of 105 erg cc-1 below the Curie temperature. Furthermore, density functional theory calculations reveal that both the monolayer and bulk VI3 are ferromagnetic insulators, and the magnetic moment of the system arises mainly from the d orbital of the V atom. These findings open a feasible avenue to fabricating TEM specimens of air-sensitive layered materials, providing an in-depth comprehensive understanding of a layered ferromagnetic VI3.
Collapse
Affiliation(s)
- Wenjie Wang
- College of Science, China Agricultural University, Beijing, 100083, China
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
| | - Rong Sun
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
- Department of Materials Science and Metallurgical Engineering and Inorganic Chemistry, University of Cadiz, Cadiz, 11003, Spain.
| | - Wei Shen
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
- The Institute of Technological Sciences, Wuhan University, Wuhan, 430074, China
| | - Zhiyan Jia
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
- Institute of Quantum Materials and Devices, School of Materials Science and Engineering, Tiangong University, Tianjin, 300387, China
| | - Francis Leonard Deepak
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
| | - Yujie Zhang
- College of Science, Tianjin University of Technology, Tianjin, 300384, China.
| | - Zhongchang Wang
- International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-330, Portugal.
| |
Collapse
|