1
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Liu Y, Meng Q, Mahmoudi P, Wang Z, Zhang J, Yang J, Li W, Wang D, Li Z, Sorrell C, Li S. Advancing Superconductivity with Interface Engineering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2405009. [PMID: 39104281 DOI: 10.1002/adma.202405009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/01/2024] [Indexed: 08/07/2024]
Abstract
The development of superconducting materials has attracted significant attention not only for their improved performance, such as high transition temperature (TC), but also for the exploration of their underlying physical mechanisms. Recently, considerable efforts have been focused on interfaces of materials, a distinct category capable of inducing superconductivity at non-superconducting material interfaces or augmenting the TC at the interface between a superconducting material and a non-superconducting material. Here, two distinct types of interfaces along with their unique characteristics are reviewed: interfacial superconductivity and interface-enhanced superconductivity, with a focus on the crucial factors and potential mechanisms responsible for enhancing superconducting performance. A series of materials systems is discussed, encompassing both historical developments and recent progress from the perspectives of technical innovations and the exploration of new material classes. The overarching goal is to illuminate pathways toward achieving high TC, expanding the potential of superconducting parameters across interfaces, and propelling superconductivity research toward practical, high-temperature applications.
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Affiliation(s)
- Yichen Liu
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Qingxiao Meng
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Pezhman Mahmoudi
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Ziyi Wang
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Ji Zhang
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Jack Yang
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Wenxian Li
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Danyang Wang
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Zhi Li
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Chris Sorrell
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Sean Li
- UNSW Materials and Manufacturing Futures Institute, School of Materials Science and Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
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2
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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.
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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
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3
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Zhang X, Zhu T, Zhang S, Chen Z, Song A, Zhang C, Gao R, Niu W, Chen Y, Fei F, Tai Y, Li G, Ge B, Lou W, Shen J, Zhang H, Chang K, Song F, Zhang R, Wang X. Light-induced giant enhancement of nonreciprocal transport at KTaO 3-based interfaces. Nat Commun 2024; 15:2992. [PMID: 38582768 PMCID: PMC10998845 DOI: 10.1038/s41467-024-47231-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/25/2024] [Indexed: 04/08/2024] Open
Abstract
Nonlinear transport is a unique functionality of noncentrosymmetric systems, which reflects profound physics, such as spin-orbit interaction, superconductivity and band geometry. However, it remains highly challenging to enhance the nonreciprocal transport for promising rectification devices. Here, we observe a light-induced giant enhancement of nonreciprocal transport at the superconducting and epitaxial CaZrO3/KTaO3 (111) interfaces. The nonreciprocal transport coefficient undergoes a giant increase with three orders of magnitude up to 105 A-1 T-1. Furthermore, a strong Rashba spin-orbit coupling effective field of 14.7 T is achieved with abundant high-mobility photocarriers under ultraviolet illumination, which accounts for the giant enhancement of nonreciprocal transport coefficient. Our first-principles calculations further disclose the stronger Rashba spin-orbit coupling strength and the longer relaxation time in the photocarrier excitation process, bridging the light-property quantitative relationship. Our work provides an alternative pathway to boost nonreciprocal transport in noncentrosymmetric systems and facilitates the promising applications in opto-rectification devices and spin-orbitronic devices.
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Affiliation(s)
- Xu Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Tongshuai Zhu
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
- College of Science, China University of Petroleum (East China), Qingdao, 266580, China
| | - Shuai Zhang
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Zhongqiang Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Anke Song
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Chong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Rongzheng Gao
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Wei Niu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Yequan Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Fucong Fei
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Yilin Tai
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Guoan Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Binghui Ge
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Wenkai Lou
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Jie Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Kai Chang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China.
| | - Rong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
- Department of Physics, Xiamen University, Xiamen, 361005, China.
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
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4
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Zhai J, Trama M, Liu H, Zhu Z, Zhu Y, Perroni CA, Citro R, He P, Shen J. Large Nonlinear Transverse Conductivity and Berry Curvature in KTaO 3 Based Two-Dimensional Electron Gas. NANO LETTERS 2023; 23:11892-11898. [PMID: 38079285 DOI: 10.1021/acs.nanolett.3c03948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Two-dimensional electron gas (2DEG) at oxide interfaces exhibits various exotic properties stemming from interfacial inversion and symmetry breaking. In this work, we report large nonlinear transverse conductivities in the LaAlO3/KTaO3 interface 2DEG under zero magnetic field. Skew scattering was identified as the dominant origin based on the cubic scaling of nonlinear transverse conductivity with linear longitudinal conductivity and 3-fold symmetry. Moreover, gate-tunable nonlinear transport with pronounced peak and dip was observed and reproduced by our theoretical calculation. These results indicate the presence of Berry curvature hotspots and thus a large Berry curvature triplet at the oxide interface. Our theoretical calculations confirm the existence of large Berry curvatures from the avoided crossing of multiple 5d-orbit bands, orders of magnitude larger than that in transition-metal dichalcogenides. Nonlinear transport offers a new pathway to probe the Berry curvature at oxide interfaces and facilitates new applications in oxide nonlinear electronics.
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Affiliation(s)
- Jinfeng Zhai
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Mattia Trama
- Physics Department "E.R. Caianiello" and CNR-SPIN Salerno Unit, Universitá Degli Studi di Salerno, Via Giovanni Paolo II, 132, I-84084 Fisciano (Sa), Italy
- INFN─Gruppo Collegato di Salerno, I-84084 Fisciano, Italy
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany
| | - Hao Liu
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Zhifei Zhu
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Yinyan Zhu
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Carmine Antonio Perroni
- Physics Department "Ettore Pancini", Universitá Degli Studi di Napoli "Federico II", Complesso Univ. Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy
- CNR-SPIN Napoli Unit, Complesso Univ. Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy
- INFN Napoli Unit, Complesso Univ. Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy
| | - Roberta Citro
- Physics Department "E.R. Caianiello" and CNR-SPIN Salerno Unit, Universitá Degli Studi di Salerno, Via Giovanni Paolo II, 132, I-84084 Fisciano (Sa), Italy
- INFN─Gruppo Collegato di Salerno, I-84084 Fisciano, Italy
| | - Pan He
- 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
| | - Jian Shen
- 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
- Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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5
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Yin H, Wang S, Jin K. Enhanced Rashba Spin Orbit Coupling and Magnetic Behavior at Oxide Heterointerfaces by Optical Gating. J Phys Chem Lett 2023; 14:8684-8690. [PMID: 37733252 DOI: 10.1021/acs.jpclett.3c01811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Complex oxide heterointerfaces have been a hot research spot due to their rich physical phenomena and broad quantum coherence that respond to multiple external stimuli. Among these external stimuli, light is a very powerful one to manipulate properties such as carrier density and spin characteristics. However, achieving a light-magnetic correlation is in high demand for multifield responding devices, and its intrinsic mechanism remains unclear. Here, by illuminating Nd0.86Sr0.14Al0.86Ni0.14O3-SrTiO3 heterointerfaces using 360 nm light, we observe a series of interesting physical phenomena, like enhanced magnetoresistance (MR). More interestingly, a band splitting and strong Rashba spin-orbit coupling (SOC) effect occur after illumination, accompanied by a magnetic feature and thus leading to an anomalous Hall effect (AHE). Upon optical gating, the magnetism can be caused by Rashba SOC induced spin-orbit torque (SOT). The work will be sure to have great importance in both theoretical studies and all-oxide devices.
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Affiliation(s)
- Hang Yin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Shuanhu Wang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Kexin Jin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
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6
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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.
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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
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7
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Yang R, Gao Y, Wang S, Jin K. High-Mobility Magnetic Two-Dimensional Electron Gas in Engineered Oxide Interfaces. ACS APPLIED MATERIALS & INTERFACES 2023; 15:2376-2383. [PMID: 36577504 DOI: 10.1021/acsami.2c17638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The engineered interfaces of complex oxides have abundant physical properties and provide a powerful platform for the exploration of fundamental physics and emergent phenomena. In particular, research on the two-dimensional magnetic systems with high mobility remains a long-standing challenge for the discovery of quantum phase and spintronic applications. Here, we introduce a few atomic layers of the delta doping layer at LaAlO3/SrTiO3 interfaces through elaborately controllable epitaxial growth of SrRuO3. After inserting a SrRuO3 buffer layer, the interfaces exhibit a well-defined anomalous Hall effect up to 100 K and their mobility is enhanced by 3 orders of magnitude at low temperatures. More intriguingly, a large unsaturated positive magnetoresistance is created at interfaces. Combining with the density functional theory calculation, we attribute our findings to the electron transfer at interfaces and the magnetic moment of Ru4+ 4d bands. The results pave a way for further research of two-dimensional ferromagnetism and quantum transport in all-oxide systems.
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Affiliation(s)
- Ruishu Yang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry Under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an710072, China
| | - Yuqiang Gao
- Department of Physics, School of Physics and Electronic Information, Anhui Normal University, Wuhu241000, China
| | - Shuanhu Wang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry Under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an710072, China
| | - Kexin Jin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry Under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an710072, China
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8
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Wang Q, Gu Y, Chen C, Pan F, Song C. Oxide Spintronics as a Knot of Physics and Chemistry: Recent Progress and Opportunities. J Phys Chem Lett 2022; 13:10065-10075. [PMID: 36264651 DOI: 10.1021/acs.jpclett.2c02634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Transition-metal oxides (TMOs) constitute a key material family in spintronics because of mutually coupled degrees of freedom and tunable magneto-ionic properties. In this Perspective, we consider oxide spintronics as a knot of physics and chemistry and mainly discuss two current hot topics: spin-charge interconversion and magneto-ionics. First, spin-charge interconversion is focused on oxide films and heterostructures including 4d/5d heavy metal oxides (e.g., SrIrO3) and two-dimensional electron gases. Based on spin-charge interconversion, charge currents can be transformed to spin currents and generate spin-orbit torque in oxide/metal and all-oxide heterostructures. Additionally, the voltage control of magnetism in TMOs by the magneto-ionic pathway has rapidly accelerated during the past few years due to the versatile advantages of effective control, nonvolatile nature, low power cost, etc. Typical magneto-ionic oxide systems and corresponding physicochemical mechanisms will be discussed. Finally, further developments of oxide spintronics are envisioned, including material discovery, physics exploration, device design, and manipulation methods.
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Affiliation(s)
- Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Youdi Gu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
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9
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Yin H, Yang R, Wang S, Jin K. Manipulation of 2DEG at double-doped high-entropy heterointerfaces. NANOSCALE 2022; 14:9771-9780. [PMID: 35766803 DOI: 10.1039/d2nr01884e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Chemical doping is a dominating method for manipulating oxide two-dimensional electron gas (2DEG). However, enhancing the doping level while maintaining the metallic conduction remains a challenge, which limits detailed knowledge of 2DEG manipulation. Herein, we propose a concept of high-entropy heterointerface, which consists of a complex oxide (containing at least 5 elements) at either or both sides of the interface. By doubly doping Sr and Mn elements in the Nd and Al sites of NdAlO3, we grow Nd1-xSrxAl1-xMnxO3 (NSAMO) films onto SrTiO3 (STO) substrates to fabricate NSAMO/STO high-entropy heterointerfaces with different thicknesses (2-30 nm) and a wide range of doping ratios x (0.14-0.56). The 2DEG conducting behavior is maintained until x = 0.42, which is higher compared with similar studies. The varying x results in the coexistence of rich properties like a weak anti-localization (0.14-0.42), abnormal Hall effect (0.28 & 0.42), Lifshitz transition (0.42) and stable structure. These results confirm the potential of this strategy to tailor 2DEG in all-oxide interfaces.
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Affiliation(s)
- Hang Yin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Ruishu Yang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Shuanhu Wang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Kexin Jin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
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10
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Verchenko VY, Kanibolotskiy AV, Bogach AV, Znamenkov KO, Shevelkov AV. Ferromagnetic correlations in the layered van der Waals sulfide FeAl 2S 4. Dalton Trans 2022; 51:8454-8460. [PMID: 35593508 DOI: 10.1039/d2dt00671e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Transition metal-based layered compounds with van der Waals gaps between the adjacent layers are a source of two-dimensional (2D) nanomaterials with nontrivial transport and magnetic properties. 2D ferromagnets, both metals and semiconductors, can be leveraged to produce spin-polarized current in spintronic devices with tailored functionalities. Here, we report on the synthesis, crystal growth, crystal and electronic structure, and magnetic properties of the Fe-based FeAl2S4 layered sulfide. In the crystal structure, Fe and Al atoms mix on octahedral and tetrahedral sites between hexagonal layers of S atoms, which are terminated by the van der Waals gaps. Band structure calculations reveal strong electronic correlations within the semiconducting ground state, which induce ferromagnetism with the magnetic moment of 0.12μB per formula unit for a Hubbard interaction U = 5 eV and Hund's rule coupling J = 0.8 eV. Crystal growth employing chemical vapor transport reactions results in bulk cleavable crystals, which show paramagnetic Curie-Weiss behavior at high temperatures with the Fe2+ magnetic centers. At low temperatures, an anomaly is observed on the magnetic susceptibility curve, below which the magnetization shows ferromagnetic hysteresis, indicating the presence of ferromagnetic correlations in FeAl2S4.
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Affiliation(s)
- Valeriy Yu Verchenko
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia. .,National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia
| | | | - Alexey V Bogach
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
| | | | - Andrei V Shevelkov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
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11
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Niu W, Fang YW, Liu R, Wu Z, Chen Y, Gan Y, Zhang X, Zhu C, Wang L, Xu Y, Pu Y, Chen Y, Wang X. Fully Optical Modulation of the Two-Dimensional Electron Gas at the γ-Al 2O 3/SrTiO 3 Interface. J Phys Chem Lett 2022; 13:2976-2985. [PMID: 35343699 DOI: 10.1021/acs.jpclett.2c00384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two-dimensional electron gas (2DEG) formed at the heterointerface between two oxide insulators hosts plenty of emergent phenomena and provides new opportunities for electronics and photoelectronics. However, despite being long sought after, on-demand properties controlled through a fully optical illumination remain far from being explored. Herein, a giant tunability of the 2DEG at the interface of γ-Al2O3/SrTiO3 through a fully optical gating is discovered. Specifically, photon-generated carriers lead to a delicate tunability of the carrier density and the underlying electronic structure, which is accompanied by the remarkable Lifshitz transition. Moreover, the 2DEG can be optically tuned to possess a maximum Rashba spin-orbit coupling, particularly at the crossing region of the sub-bands with different symmetries. First-principles calculations essentially well explain the optical modulation of γ-Al2O3/SrTiO3. Our fully optical gating opens a new pathway for manipulating emergent properties of the 2DEGs and is promising for on-demand photoelectric devices.
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Affiliation(s)
- Wei Niu
- New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Yue-Wen Fang
- Laboratory for Materials and Structures and Tokyo Tech World Research Hub Initiative (WRHI), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- NYU-ECNU Institute of Physics, New York University Shanghai, Shanghai 200122, China
| | - Ruxin Liu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Zhenqi Wu
- New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yongda Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Yulin Gan
- Beijing National Laboratory for Condensed Matter and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoqian Zhang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chunhui Zhu
- College of Physics, Hebei Normal University, Shijiazhuang 050024, China
| | - Lixia Wang
- New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yongbing Xu
- New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Yong Pu
- New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yunzhong Chen
- Beijing National Laboratory for Condensed Matter and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
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12
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Gupta A, Silotia H, Kumari A, Dumen M, Goyal S, Tomar R, Wadehra N, Ayyub P, Chakraverty S. KTaO 3 -The New Kid on the Spintronics Block. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106481. [PMID: 34961972 DOI: 10.1002/adma.202106481] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/16/2021] [Indexed: 06/14/2023]
Abstract
Long after the heady days of high-temperature superconductivity, the oxides came back into the limelight in 2004 with the discovery of the 2D electron gas (2DEG) in SrTiO3 (STO) and several heterostructures based on it. Not only do these materials exhibit interesting physics, but they have also opened up new vistas in oxide electronics and spintronics. However, much of the attention has recently shifted to KTaO3 (KTO), a material with all the "good" properties of STO (simple cubic structure, high mobility, etc.) but with the additional advantage of a much larger spin-orbit coupling. In this state-of-the-art review of the fascinating world of KTO, it is attempted to cover the remarkable progress made, particularly in the last five years. Certain unsolved issues are also indicated, while suggesting future research directions as well as potential applications. The range of physical phenomena associated with the 2DEG trapped at the interfaces of KTO-based heterostructures include spin polarization, superconductivity, quantum oscillations in the magnetoresistance, spin-polarized electron transport, persistent photocurrent, Rashba effect, topological Hall effect, and inverse Edelstein Effect. It is aimed to discuss, on a single platform, the various fabrication techniques, the exciting physical properties and future application possibilities of this family of materials.
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Affiliation(s)
- Anshu Gupta
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Harsha Silotia
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Anamika Kumari
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Manish Dumen
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Saveena Goyal
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Ruchi Tomar
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Neha Wadehra
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
| | - Pushan Ayyub
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India
| | - Suvankar Chakraverty
- Quantum Materials and Devices Unit, Institute of Nano Science and Technology, Sector-81, Mohali, Punjab, 140306, India
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13
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Chen X, Zhang J, Liu B, Hu F, Shen B, Sun J. Two-dimensional conducting states in infinite-layer oxide/perovskite oxide hetero-structures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:035003. [PMID: 34663765 DOI: 10.1088/1361-648x/ac30b6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
Heterointerfaces sandwiched by oxides of dissimilar crystal structures will show strong interface reconstruction, leading to distinct interfacial effect arising from unusual physics. Here, we present a theoretical investigation on the interfaces between infinite-layer oxide and perovskite oxide (SrCuO2/SrTiO3and SrCuO2/KTaO3). Surprisingly, we found well-defined two-dimensional electron gas (2DEG), stemming from atomic reconstruction and polar discontinuity at interface. Moreover, the 2DEG resides in both the TiO2and CuO2interfacial layers, unlike LaAlO3/SrTiO3for which 2DEG exists only in the TiO2interfacial layer. More than that, no metal-to-insulator transition is observed as the SrCuO2layer thickness decreases to one unit cell, i.e., the metallicity of the new interface is robust. Further investigations show more unique features of the 2DEG. Due to the absence of apical oxygen at the SrCuO2/SrTiO3(KTaO3) interface, the conducting states in the interface TiO2(TaO2) layer follows thedxy<d3z2-r2<dxz/yzorbital order rather than thedxy<dxz/yzorbital order of paradigm LaAlO3/SrTiO3(KTaO3), exhibiting enhanced interfacial conduction. This work suggests the great potential of heterointerfaces composed of non-isostructural oxides for fundamental research.
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Affiliation(s)
- Xiaobing Chen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jine Zhang
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
| | - Banggui Liu
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Fengxia Hu
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
- Spintronics Institute, University of Jinan, Jinan, Shandong 250022, People's Republic of China
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14
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Li M, Zhou Y, Chen Y, Yang R, Wei X, Wang S, Jin K. Effect of Rare Earth Elements at Amorphous ReAlO 3/SrTiO 3 (Re = La, Pr, Nd, Sm, Gd, and Tm) Heterointerfaces. J Phys Chem Lett 2021; 12:1657-1663. [PMID: 33555878 DOI: 10.1021/acs.jpclett.0c03685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Although the amorphous two-dimensional electron gas (a-2DEG) of oxides provides new opportunities to explore nanoelectronic as well as quantum devices, the intrinsic effect of rare earth (Re = La, Pr, Nd, Sm, Gd, and Tm) elements at ReAlO3/SrTiO3 heterointerfaces is still largely unknown and needs to be addressed systematically. Herein, we first propose that the ionization potential of Re elements is a critical factor for the 2DEG fabricated by chemical spin coating. Furthermore, the photoresponsive properties of heterointerfaces are investigated comprehensively with the ionization potential ranging from 35.79 to 41.69 eV. The results show that the sheet resistances significantly increase with increasing the ionization potential, and a resistance upturn phenomenon is observed at TmAlO3/SrTiO3 heterointerfaces, which can be attributed to the weak localization effect theoretically. The most important observation is the dramatic transition from negative (-178.3%, Re = La) to positive (+89.9%, Re = Gd) photoresponse at ReAlO3/SrTiO3 heterointerfaces under the irradiation of 405 nm light at 50 K. More remarkably, a unique recovery behavior of transient-persistent photoconductivity coexistence at low temperatures is discovered at the TmAlO3/SrTiO3 heterointerface. This work reveals an effective approach to tune the transport and photoresponsive properties by changing Re elements and paves the way for the application of all-oxide devices.
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Affiliation(s)
- Ming Li
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - You Zhou
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yunhai Chen
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Ruishu Yang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xiangyang Wei
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Shuanhu Wang
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
| | - Kexin Jin
- Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
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15
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Wu N, Zhang XJ, Liu BG. Strain-enhanced giant Rashba spin splitting in ultrathin KTaO 3 films for spin-polarized photocurrents. RSC Adv 2020; 10:44088-44095. [PMID: 35517182 PMCID: PMC9058490 DOI: 10.1039/d0ra08745a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 12/26/2022] Open
Abstract
Strong Rashba effects at semiconductor surfaces and interfaces have attracted great attention for basic scientific exploration and practical applications. Here, we show through first-principles investigation that applying biaxial stress can cause tunable and giant Rashba effects in ultrathin KTaO3 (KTO) (001) films with the most stable surfaces. When increasing the in-plane compressive strain to −5%, the Rashba spin splitting energy reaches ER = 140 meV, corresponding to the Rashba coupling constant αR = 1.3 eV Å. We investigate its strain-dependent crystal structures, energy bands, and related properties, and thereby elucidate the mechanism for the giant Rashba effects. Further calculations show that the giant Rashba spin splitting can remain or be enhanced when capping layer and/or Si substrate are added, and a SrTiO3 capping can make the Rashba spin splitting energy reach the record 190 meV. Furthermore, it is elucidated that strong circular photogalvanic effect can be achieved for spin-polarized photocurrents in the KTO thin films or related heterostructures, which is promising for future spintronic and optoelectronic applications. Strong Rashba effects at semiconductor surfaces and interfaces have attracted attention for exploration and applications. We show with first-principles investigation that applying biaxial stress can cause tunable and giant Rashba effects in ultrathin KTaO3 (KTO) (001) films.![]()
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Affiliation(s)
- Ning Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190 China .,School of Physical Sciences, University of Chinese Academy of Sciences Beijing 100190 China
| | - Xue-Jing Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190 China .,School of Physical Sciences, University of Chinese Academy of Sciences Beijing 100190 China
| | - Bang-Gui Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190 China .,School of Physical Sciences, University of Chinese Academy of Sciences Beijing 100190 China
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16
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Ahamed I, Seriani N, Gebauer R, Kashyap A. Heterostructures of ε-Fe 2O 3 and α-Fe 2O 3: insights from density functional theory. RSC Adv 2020; 10:27474-27480. [PMID: 35516952 PMCID: PMC9055593 DOI: 10.1039/d0ra04020g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/17/2020] [Indexed: 02/04/2023] Open
Abstract
Many materials used in energy devices or applications suffer from the problem of electron-hole pair recombination. One promising way to overcome this problem is the use of heterostructures in place of a single material. If an electric dipole forms at the interface, such a structure can lead to a more efficient electron-hole pair separation and thus prevent recombination. Here we model and study a heterostructure comprised of two polymorphs of Fe2O3. Each one of the two polymorphs, α-Fe2O3 and ε-Fe2O3, individually shows promise for applications in photoelectrochemical cells. The heterostructure of these two materials is modeled by means of density functional theory. We consider both ferromagnetic as well as anti-ferromagnetic couplings at the interface between the two systems. Both individual oxides are insulating in nature and have an anti-ferromagnetic spin arrangement in their ground state. The same properties are found also in their heterostructure. The highest occupied electronic orbitals of the combined system are localized at the interface between the two iron-oxides. The localization of charges at the interface is characterized by electrons residing close to the oxygen atoms of ε-Fe2O3 and electron-holes localized on the iron atoms of α-Fe2O3, just around the interface. The band alignment at the interface of the two oxides shows a type-III broken band-gap heterostructure. The band edges of α-Fe2O3 are higher in energy than those of ε-Fe2O3. This band alignment favours a spontaneous transfer of excited photo-electrons from the conduction band of α- to the conduction band of ε-Fe2O3. Similarly, photo-generated holes are transferred from the valence band of ε- to the valence band of α-Fe2O3. Thus, the interface favours a spontaneous separation of electrons and holes in space. The conduction band of ε-Fe2O3, lying close to the valence band of α-Fe2O3, can result in band-to-band tunneling of electrons which is a characteristic property of such type-III broken band-gap heterostructures and has potential applications in tunnel field-effect transistors.
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Affiliation(s)
- Imran Ahamed
- School of Basic Sciences, Indian Institute of Technology Mandi Himachal Pradesh 175005 India
| | - Nicola Seriani
- The Abdus Salam International Centre for Theoretical Physics (ICTP) Strada Costiera 11 34151 Trieste Italy
| | - Ralph Gebauer
- The Abdus Salam International Centre for Theoretical Physics (ICTP) Strada Costiera 11 34151 Trieste Italy
| | - Arti Kashyap
- School of Basic Sciences, School of Computing and Electrical Engineering, Indian Institute of Technology Mandi Himachal Pradesh 175005 India
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17
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Zhang J, Zhang H, Zhang H, Ma Y, Chen X, Meng F, Qi S, Chen Y, Hu F, Zhang Q, Liu B, Shen B, Zhao W, Han W, Sun J. Long-Range Magnetic Order in Oxide Quantum Wells Hosting Two-Dimensional Electron Gases. ACS APPLIED MATERIALS & INTERFACES 2020; 12:28775-28782. [PMID: 32459951 DOI: 10.1021/acsami.0c05332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To incorporate spintronics functionalities into two-dimensional devices, it is strongly desired to get two-dimensional electron gases (2DEGs) with high spin polarization. Unfortunately, the magnetic characteristics of the typical 2DEG at the LaAlO3/SrTiO3 interface are very weak due to the nonmagnetic character of SrTiO3 and LaAlO3. While most of the previous works focused on perovskite oxides, here, we extended the exploration for magnetic 2DEG beyond the scope of perovskite combinations, composing 2DEG with SrTiO3 and NaCl-structured EuO that owns a large saturation magnetization and a fairly high Curie temperature. We obtained the 2DEGs that show long-range magnetic order and thus unusual behaviors marked by isotropic butterfly shaped magnetoresistance and remarkable anomalous Hall effect. We found evidence for the presence of more conductive domain walls than elsewhere in the oxide layer where the 2DEG resides. More than that, a relation between interfacial magnetism and carrier density is established. On this basis, the intermediate magnetic states between short-range and long-range ordered states can be achieved. The present work provides guidance for the design of high-performance magnetic 2DEGs.
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Affiliation(s)
- Jine Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Hui Zhang
- Fert Beijing Institute, School of Microelectronics, Beijing Advanced Innovation Center for Big Data and Brain Computing, Beihang University, Beijing 100191, People's Republic of China
| | - Hongrui Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yang Ma
- International Centre for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Centre of Quantum Matter, Beijing 100871, People's Republic of China
| | - Xiaobing Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Fanqi Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Shaojin Qi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yuansha Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Fengxia Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Banggui Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Weisheng Zhao
- Fert Beijing Institute, School of Microelectronics, Beijing Advanced Innovation Center for Big Data and Brain Computing, Beihang University, Beijing 100191, People's Republic of China
| | - Wei Han
- International Centre for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Centre of Quantum Matter, Beijing 100871, People's Republic of China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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18
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Zhang H, Ma Y, Zhang H, Chen X, Wang S, Li G, Yun Y, Yan X, Chen Y, Hu F, Cai J, Shen B, Han W, Sun J. Thermal Spin Injection and Inverse Edelstein Effect of the Two-Dimensional Electron Gas at EuO-KTaO 3 Interfaces. NANO LETTERS 2019; 19:1605-1612. [PMID: 30715894 DOI: 10.1021/acs.nanolett.8b04509] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
With the help of the two-dimensional electron gas (2DEG) at the LaAlO3-SrTiO3 interface, spin and charge currents can be interconverted. However, the conversion efficiency has been strongly depressed by LaAlO3, which blocks spin transmission. It is therefore highly desired to explore 2DEGs sandwiched between ferromagnetic insulators that are transparent for magnons. By constructing epitaxial heterostructure with ferromagnetic EuO, which is conducting for spin current but insulating for electric current, and KTaO3, we successfully obtained the 2DEGs, which can receive thermally injected spin current directly from EuO and convert the spin current to charge current via inverse Edelstein effect of the interface. Strong dependence of the spin Seebeck coefficient on the layer thickness of EuO is further observed and the propagation length for non-equilibrium magnons in EuO has been determined. The present work demonstrates the great potential of the 2DEGs formed by ferromagnetic oxides for spin caloritronics.
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Affiliation(s)
- Hongrui Zhang
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Yang Ma
- International Centre for Quantum Materials , School of Physics, Peking University , Beijing 100871 , People's Republic of China
- Collaborative Innovation Centre of Quantum Matter , Beijing 100871 , People's Republic of China
| | - Hui Zhang
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Xiaobing Chen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Shuanhu Wang
- Shanxi Key Laboratory of Condensed Matter Structures and Properties, School of Science , Northwestern Polytechnic University , Xi'an 710072 , People's Republic of China
| | - Gang Li
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Yu Yun
- International Centre for Quantum Materials , School of Physics, Peking University , Beijing 100871 , People's Republic of China
- Collaborative Innovation Centre of Quantum Matter , Beijing 100871 , People's Republic of China
| | - Xi Yan
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Yuansha Chen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Fengxia Hu
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , People's Republic of China
| | - Jianwang Cai
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , People's Republic of China
| | - Wei Han
- International Centre for Quantum Materials , School of Physics, Peking University , Beijing 100871 , People's Republic of China
- Collaborative Innovation Centre of Quantum Matter , Beijing 100871 , People's Republic of China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
- School of Physics , University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , People's Republic of China
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19
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Cortés N, Ávalos-Ovando O, Rosales L, Orellana PA, Ulloa SE. Tunable Spin-Polarized Edge Currents in Proximitized Transition Metal Dichalcogenides. PHYSICAL REVIEW LETTERS 2019; 122:086401. [PMID: 30932605 DOI: 10.1103/physrevlett.122.086401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/05/2018] [Indexed: 06/09/2023]
Abstract
We explore proximity-induced ferromagnetism on transition metal dichalcogenides (TMDs), focusing on molybdenum ditelluride ribbons with zigzag edges, deposited on ferromagnetic europium oxide (EuO). A tight-binding model incorporates exchange and Rashba fields induced by proximity to EuO or similar substrates. For in-gap Fermi levels, electronic modes in the nanoribbon are localized along the edges, acting as one-dimensional (1D) conducting channels with tunable spin-polarized currents. TMDs on magnetic substrates can become very useful in spintronics, providing versatile platforms to study the proximity effects and electronic interactions in complex 1D systems.
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Affiliation(s)
- Natalia Cortés
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
- Department of Physics and Astronomy, and Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701-2979, USA
| | - O Ávalos-Ovando
- Department of Physics and Astronomy, and Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701-2979, USA
| | - L Rosales
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
| | - P A Orellana
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
| | - S E Ulloa
- Department of Physics and Astronomy, and Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701-2979, USA
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