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Qu J, Cuddy EF, Han X, Liu J, Li H, Zeng YJ, Moritz B, Devereaux TP, Kirchmann PS, Shen ZX, Sobota JA. Screening of Polar Electron-Phonon Interactions near the Surface of the Rashba Semiconductor BiTeCl. PHYSICAL REVIEW LETTERS 2024; 133:106401. [PMID: 39303246 DOI: 10.1103/physrevlett.133.106401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/19/2024] [Accepted: 07/29/2024] [Indexed: 09/22/2024]
Abstract
Understanding electron-phonon coupling in noncentrosymmetric materials is critical for controlling the internal fields which give rise to Rashba interactions. We apply time- and angle-resolved photoemission spectroscopy (trARPES) to study coherent phonons in the surface and bulk regions of the polar semiconductor BiTeCl. Aided by ab initio calculations, our measurements reveal the coupling of out-of-plane A_{1} modes and an in-plane E_{2} mode. By considering how these modes modulate the electric dipole moment in each unit cell, we show that the polar A_{1} modes are more effectively screened in the metallic surface region, while the nonpolar E_{2} mode couples in both regions. In addition to informing strategies to optically manipulate Rashba interactions, this Letter has broader implications for the behavior of electron-phonon coupling in systems characterized by inhomogeneous dielectric environments.
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Affiliation(s)
- J Qu
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | | | - X Han
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | | | | | | | | | - T P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | | | - Z-X Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
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2
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Lin YY, Liu FY, Chen IC, Tsai HY, Huang JW, Lin JH, Chen CC. Photocatalytic reduction of carbon dioxide by BiTeX (X = Cl, Br, I) under visible-light irradiation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121536. [PMID: 38909577 DOI: 10.1016/j.jenvman.2024.121536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 06/15/2024] [Accepted: 06/17/2024] [Indexed: 06/25/2024]
Abstract
In this study, a series of BiTeX (X = Cl, Br, I) photocatalysts were successfully synthesized via a simple hydrothermal method. The synthesis process involved dissolving BiX3 and Te powder in toluene to identify the most efficient material for photocatalytic activity. The main objective of this approach is to facilitate the conversion of carbon dioxide into sustainable solar fuels, such as alcohols and hydrocarbons, offering an appealing solution to address environmental concerns and energy crises. The BiTeX photocatalysts demonstrated significant proficiency in converting CO2 into CH4, particularly BiTeCl exhibited a notable photocatalytic conversion rate of up to 0.51 μmolg-1h-1. The optimized BiTeX photocatalysts displayed a gradual and selective transition from CO2 to CH4, ultimately producing valuable hydrocarbons (C2+). Furthermore, owing to their ability to reduce CO2, these photocatalysts show promise as materials for mitigating environmental pollution.
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Affiliation(s)
- Yu-Yun Lin
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan
| | - Fu-Yu Liu
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan; Department of Chemistry, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - I-Chia Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Hwei-Yan Tsai
- Department of Medical Applied Chemistry, Chung Shan Medical University, Taichung, 402, Taiwan; Department of Medical Education, Chung Shan Medical University Hospital, Taichung, 402, Taiwan
| | - Jhen-Wei Huang
- Department of Medical Applied Chemistry, Chung Shan Medical University, Taichung, 402, Taiwan
| | - Jia-Hao Lin
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan
| | - Chiing-Chang Chen
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan.
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3
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Krizman G, Zakusylo T, Sajeev L, Hajlaoui M, Takashiro T, Rosmus M, Olszowska N, Kołodziej JJ, Bauer G, Caha O, Springholz G. A Novel Ferroelectric Rashba Semiconductor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2310278. [PMID: 38100676 DOI: 10.1002/adma.202310278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Fast, reversible, and low-power manipulation of the spin texture is crucial for next generation spintronic devices like non-volatile bipolar memories, switchable spin current injectors or spin field effect transistors. Ferroelectric Rashba semiconductors (FERSC) are the ideal class of materials for the realization of such devices. Their ferroelectric character enables an electronic control of the Rashba-type spin texture by means of the reversible and switchable polarization. Yet, only very few materials are established to belong to this class of multifunctional materials. Here, Pb1- x Gex Te is unraveled as a novel FERSC system down to nanoscale. The ferroelectric phase transition and concomitant lattice distortion are demonstrated by temperature dependent X-ray diffraction, and their effect on electronic properties are measured by angle-resolved photoemission spectroscopy. In few nanometer-thick epitaxial heterostructures, a large Rashba spin-splitting is exhibiting a wide tuning range as a function of temperature and Ge content. This work defines Pb1- x Gex Te as a high-potential FERSC system for spintronic applications.
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Affiliation(s)
- Gauthier Krizman
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
| | - Tetiana Zakusylo
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
| | - Lakshmi Sajeev
- Department of Condensed Matter Physics, Masaryk University, Kotlárská 2, Brno, 61137, Czech Republic
| | - Mahdi Hajlaoui
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
| | - Takuya Takashiro
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
| | - Marcin Rosmus
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, Krakow, 30-392, Poland
| | - Natalia Olszowska
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, Krakow, 30-392, Poland
| | - Jacek J Kołodziej
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, Krakow, 30-392, Poland
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Ul. Prof. Stanislawa Lojasiewizca 11, Krakow, 30-348, Poland
| | - Günther Bauer
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
| | - Ondrej Caha
- Department of Condensed Matter Physics, Masaryk University, Kotlárská 2, Brno, 61137, Czech Republic
| | - Gunther Springholz
- Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenberger Strasse 69, Linz, 4040, Austria
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4
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Rusetsky VS, Golyashov VA, Eremeev SV, Kustov DA, Rusinov IP, Shamirzaev TS, Mironov AV, Demin AY, Tereshchenko OE. New Spin-Polarized Electron Source Based on Alkali Antimonide Photocathode. PHYSICAL REVIEW LETTERS 2022; 129:166802. [PMID: 36306756 DOI: 10.1103/physrevlett.129.166802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
New spin-dependent photoemission properties of alkali antimonide semiconductor cathodes are predicted based on the detected optical spin orientation effect and DFT band structure calculations. Using these results, the Na_{2}KSb/Cs_{3}Sb heterostructure is designed as a spin-polarized electron source in combination with the Al_{0.11}Ga_{0.89}As target as a spin detector with spatial resolution. In the Na_{2}KSb/Cs_{3}Sb photocathode, spin-dependent photoemission properties were established through detection of a high degree of photoluminescence polarization and high polarization of the photoemitted electrons. It was found that the multi-alkali photocathode can provide electron beams with emittance very close to the limits imposed by the electron thermal energy. The vacuum tablet-type sources of spin-polarized electrons have been proposed for accelerators, which can exclude the construction of the photocathode growth chambers for photoinjectors.
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Affiliation(s)
- V S Rusetsky
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- CJSC "Ekran FEP", Novosibirsk 630060, Russia
| | - V A Golyashov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol'tsovo 630559, Russia
- Novosibirsk State University, Novosibirsk 630090 Russia
| | - S V Eremeev
- Institute of Strength Physics and Materials Science, Tomsk 634055, Russia
| | - D A Kustov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - I P Rusinov
- Tomsk State University, Tomsk 634050, Russia
| | - T S Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090 Russia
| | - A V Mironov
- CJSC "Ekran FEP", Novosibirsk 630060, Russia
| | - A Yu Demin
- CJSC "Ekran FEP", Novosibirsk 630060, Russia
| | - O E Tereshchenko
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol'tsovo 630559, Russia
- Novosibirsk State University, Novosibirsk 630090 Russia
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5
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Cai L, Yu C, Zhao W, Li Y, Feng H, Zhou HA, Wang L, Zhang X, Zhang Y, Shi Y, Zhang J, Yang L, Jiang W. The Giant Spin-to-Charge Conversion of the Layered Rashba Material BiTeI. NANO LETTERS 2022; 22:7441-7448. [PMID: 36099337 DOI: 10.1021/acs.nanolett.2c02354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rashba spin-orbit coupling (SOC) could facilitate an efficient interconversion between spin and charge currents. Among various systems, BiTeI holds one of the largest Rashba-type spin splittings. Unlike other Rashba systems (e.g., Bi/Ag and Bi2Se3), an experimental investigation of the spin-to-charge interconversion in BiTeI remains to be explored. Through performing an angle-resolved photoemission spectroscopy (ARPES) measurement, such a large Rashba-type spin splitting with a Rashba parameter αR = 3.68 eV Å is directly identified. By studying the spin pumping effect in the BiTeI/NiFe bilayer, we reveal a very large inverse Rashba-Edelstein length λIREE ≈ 1.92 nm of BiTeI at room temperature. Furthermore, the λIREE monotonously increases to 5.00 nm at 60 K, indicating an enhanced Rashba SOC at low temperature. These results suggest that BiTeI films with the giant Rashba SOC are promising for achieving efficient spin-to-charge interconversion, which could be implemented for building low-power-consumption spin-orbitronic devices.
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Affiliation(s)
- Li Cai
- 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
| | - Chenglin Yu
- 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
| | - Wenxuan 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
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Yong Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongmei Feng
- 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
| | - Heng-An Zhou
- 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
| | - Ledong 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
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Xiaofang Zhang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinsong Zhang
- 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
| | - Lexian Yang
- 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
| | - 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
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6
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Spanning Fermi arcs in a two-dimensional magnet. Nat Commun 2022; 13:5309. [PMID: 36085323 PMCID: PMC9463448 DOI: 10.1038/s41467-022-32948-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 08/24/2022] [Indexed: 11/08/2022] Open
Abstract
The discovery of topological states of matter has led to a revolution in materials research. When external or intrinsic parameters break symmetries, global properties of topological materials change drastically. A paramount example is the emergence of Weyl nodes under broken inversion symmetry. While a rich variety of non-trivial quantum phases could in principle also originate from broken time-reversal symmetry, realizing systems that combine magnetism with complex topological properties is remarkably elusive. Here, we demonstrate that giant open Fermi arcs are created at the surface of ultrathin hybrid magnets where the Fermi-surface topology is substantially modified by hybridization with a heavy-metal substrate. The interplay between magnetism and topology allows us to control the shape and the location of the Fermi arcs by tuning the magnetization direction. The hybridization points in the Fermi surface can be attributed to a non-trivial mixed topology and induce hot-spots in the Berry curvature, dominating spin and charge transport as well as magneto-electric coupling effects. It has been predicted that elemental Iron, with low dimensionality, will be a topological metal hosting Weyl nodes. Here, Chen et al. grow iron on tungsten, a heavy metal with a strong spin-orbit interaction, and using momentum microscopy, show the emergence of giant open Fermi arcs which can be shaped by varying the magnetization of the iron.
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7
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Bianca G, Trovatello C, Zilli A, Zappia MI, Bellani S, Curreli N, Conticello I, Buha J, Piccinni M, Ghini M, Celebrano M, Finazzi M, Kriegel I, Antonatos N, Sofer Z, Bonaccorso F. Liquid-Phase Exfoliation of Bismuth Telluride Iodide (BiTeI): Structural and Optical Properties of Single-/Few-Layer Flakes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:34963-34974. [PMID: 35876692 PMCID: PMC9354013 DOI: 10.1021/acsami.2c07704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Bismuth telluride halides (BiTeX) are Rashba-type crystals with several potential applications ranging from spintronics and nonlinear optics to energy. Their layered structures and low cleavage energies allow their production in a two-dimensional form, opening the path to miniaturized device concepts. The possibility to exfoliate bulk BiTeX crystals in the liquid represents a useful tool to formulate a large variety of functional inks for large-scale and cost-effective device manufacturing. Nevertheless, the exfoliation of BiTeI by means of mechanical and electrochemical exfoliation proved to be challenging. In this work, we report the first ultrasonication-assisted liquid-phase exfoliation (LPE) of BiTeI crystals. By screening solvents with different surface tension and Hildebrandt parameters, we maximize the exfoliation efficiency by minimizing the Gibbs free energy of the mixture solvent/BiTeI crystal. The most effective solvents for the BiTeI exfoliation have a surface tension close to 28 mN m-1 and a Hildebrandt parameter between 19 and 25 MPa0.5. The morphological, structural, and chemical properties of the LPE-produced single-/few-layer BiTeI flakes (average thickness of ∼3 nm) are evaluated through microscopic and optical characterizations, confirming their crystallinity. Second-harmonic generation measurements confirm the non-centrosymmetric structure of both bulk and exfoliated materials, revealing a large nonlinear optical response of BiTeI flakes due to the presence of strong quantum confinement effects and the absence of typical phase-matching requirements encountered in bulk nonlinear crystals. We estimated a second-order nonlinearity at 0.8 eV of |χ(2)| ∼ 1 nm V-1, which is 10 times larger than in bulk BiTeI crystals and is of the same order of magnitude as in other semiconducting monolayers (e.g., MoS2).
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Affiliation(s)
- Gabriele Bianca
- Graphene
Labs, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
- Dipartimento
di Chimica e Chimica Industriale, Università
degli Studi di Genova, via Dodecaneso 31, 16146 Genoa, Italy
| | - Chiara Trovatello
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Attilio Zilli
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Marilena Isabella Zappia
- BeDimensional
S.p.A., via Lungotorrente
Secca 30R, 16163 Genova, Italy
- Department
of Physics, University of Calabria, Via P. Bucci cubo 31/C Rende, Cosenza 87036, Italy
| | | | - Nicola Curreli
- Functional
Nanosystems, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy
| | - Irene Conticello
- BeDimensional
S.p.A., via Lungotorrente
Secca 30R, 16163 Genova, Italy
| | - Joka Buha
- Nanochemistry
Department, Istituto Italiano di Tecnologia, via Morego 30, Genova 16163, Italy
| | - Marco Piccinni
- Graphene
Labs, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
- Dipartimento
di Chimica e Chimica Industriale, Università
degli Studi di Genova, via Dodecaneso 31, 16146 Genoa, Italy
| | - Michele Ghini
- Functional
Nanosystems, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy
| | - Michele Celebrano
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Marco Finazzi
- Dipartimento
di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Ilka Kriegel
- Functional
Nanosystems, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy
| | - Nikolas Antonatos
- Department
of Inorganic Chemistry, University of Chemistry
and Technology Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Zdeněk Sofer
- Department
of Inorganic Chemistry, University of Chemistry
and Technology Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Francesco Bonaccorso
- Graphene
Labs, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
- BeDimensional
S.p.A., via Lungotorrente
Secca 30R, 16163 Genova, Italy
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8
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Nascimento GM, Ogoshi E, Fazzio A, Acosta CM, Dalpian GM. High-throughput inverse design and Bayesian optimization of functionalities: spin splitting in two-dimensional compounds. Sci Data 2022; 9:195. [PMID: 35487920 PMCID: PMC9054849 DOI: 10.1038/s41597-022-01292-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/03/2022] [Indexed: 11/15/2022] Open
Abstract
The development of spintronic devices demands the existence of materials with some kind of spin splitting (SS). In this Data Descriptor, we build a database of ab initio calculated SS in 2D materials. More than that, we propose a workflow for materials design integrating an inverse design approach and a Bayesian inference optimization. We use the prediction of SS prototypes for spintronic applications as an illustrative example of the proposed workflow. The prediction process starts with the establishment of the design principles (the physical mechanism behind the target properties), that are used as filters for materials screening, and followed by density functional theory (DFT) calculations. Applying this process to the C2DB database, we identify and classify 358 2D materials according to SS type at the valence and/or conduction bands. The Bayesian optimization captures trends that are used for the rationalized design of 2D materials with the ideal conditions of band gap and SS for potential spintronics applications. Our workflow can be applied to any other material property.
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Affiliation(s)
- Gabriel M Nascimento
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, SP, Brazil
| | - Elton Ogoshi
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, SP, Brazil
| | - Adalberto Fazzio
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, SP, Brazil
- Brazilian Nanotechnology National Laboratory (LNNano), CNPEM, 13083-970, Campinas, São Paulo, Brazil
| | - Carlos Mera Acosta
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, SP, Brazil.
| | - Gustavo M Dalpian
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, SP, Brazil.
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9
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Deng H, Zhang C, Liang W, Zhang XX, Luo SN. Hot carrier dynamics of BiTeI with large Rashba spin splitting. RSC Adv 2022; 12:16479-16485. [PMID: 35754880 PMCID: PMC9167645 DOI: 10.1039/d2ra01978g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 05/13/2022] [Indexed: 11/21/2022] Open
Abstract
We present a time-resolved ultrafast optical spectroscopy study on BiTeI, a noncentrosymmetric semiconductor with large spin–orbit splitting.
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Affiliation(s)
- Hongze Deng
- The Peac Institute of Multiscale Sciences, Chengdu, Sichuan, People's Republic of China
| | - Chenhui Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Weizheng Liang
- The Peac Institute of Multiscale Sciences, Chengdu, Sichuan, People's Republic of China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Sheng-Nian Luo
- School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, People's Republic of China
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10
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Shikin AM, Rybkina AA, Estyunin DA, Klimovskikh II, Rybkin AG, Filnov SO, Koroleva AV, Shevchenko EV, Likholetova MV, Voroshnin VY, Petukhov AE, Kokh KA, Tereshchenko OE, Petaccia L, Di Santo G, Kumar S, Kimura A, Skirdkov PN, Zvezdin KA, Zvezdin AK. Non-monotonic variation of the Kramers point band gap with increasing magnetic doping in BiTeI. Sci Rep 2021; 11:23332. [PMID: 34857800 PMCID: PMC8639783 DOI: 10.1038/s41598-021-02493-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/27/2021] [Indexed: 12/01/2022] Open
Abstract
Polar Rashba-type semiconductor BiTeI doped with magnetic elements constitutes one of the most promising platforms for the future development of spintronics and quantum computing thanks to the combination of strong spin-orbit coupling and internal ferromagnetic ordering. The latter originates from magnetic impurities and is able to open an energy gap at the Kramers point (KP gap) of the Rashba bands. In the current work using angle-resolved photoemission spectroscopy (ARPES) we show that the KP gap depends non-monotonically on the doping level in case of V-doped BiTeI. We observe that the gap increases with V concentration until it reaches 3% and then starts to mitigate. Moreover, we find that the saturation magnetisation of samples under applied magnetic field studied by superconducting quantum interference device (SQUID) magnetometer has a similar behaviour with the doping level. Theoretical analysis shows that the non-monotonic behavior can be explained by the increase of antiferromagnetic coupled atoms of magnetic impurity above a certain doping level. This leads to the reduction of the total magnetic moment in the domains and thus to the mitigation of the KP gap as observed in the experiment. These findings provide further insight in the creation of internal magnetic ordering and consequent KP gap opening in magnetically-doped Rashba-type semiconductors.
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Affiliation(s)
- A M Shikin
- Saint Petersburg State University, Saint Petersburg, 198504, Russia.
| | - A A Rybkina
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - D A Estyunin
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - I I Klimovskikh
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - A G Rybkin
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - S O Filnov
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - A V Koroleva
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - E V Shevchenko
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - M V Likholetova
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - V Yu Voroshnin
- Saint Petersburg State University, Saint Petersburg, 198504, Russia.,Helmholtz-Zentrum Berlin für Materialien und Energie, BESSY II, 12489, Berlin, Germany
| | - A E Petukhov
- Saint Petersburg State University, Saint Petersburg, 198504, Russia
| | - K A Kokh
- Saint Petersburg State University, Saint Petersburg, 198504, Russia.,Kemerovo State University, Kemerovo, 650000, Russia.,Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, 630090, Russia
| | - O E Tereshchenko
- Saint Petersburg State University, Saint Petersburg, 198504, Russia.,Novosibirsk State University, Novosibirsk, 630090, Russia.,A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, 630090, Russia
| | - L Petaccia
- Elettra Sincrotrone Trieste, 34149, Trieste, Italy
| | - G Di Santo
- Elettra Sincrotrone Trieste, 34149, Trieste, Italy
| | - S Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-0046, Japan
| | - A Kimura
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
| | - P N Skirdkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, 119991, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russia
| | - K A Zvezdin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, 119991, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russia
| | - A K Zvezdin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, 119991, Russia.,P.N. Lebedev Physical Institute of Russian Academy of Sciences, Moscow, 119991, Russia
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11
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Ünzelmann M, Bentmann H, Figgemeier T, Eck P, Neu JN, Geldiyev B, Diekmann F, Rohlf S, Buck J, Hoesch M, Kalläne M, Rossnagel K, Thomale R, Siegrist T, Sangiovanni G, Sante DD, Reinert F. Momentum-space signatures of Berry flux monopoles in the Weyl semimetal TaAs. Nat Commun 2021; 12:3650. [PMID: 34131129 PMCID: PMC8206138 DOI: 10.1038/s41467-021-23727-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/12/2021] [Indexed: 11/16/2022] Open
Abstract
Since the early days of Dirac flux quantization, magnetic monopoles have been sought after as a potential corollary of quantized electric charge. As opposed to magnetic monopoles embedded into the theory of electromagnetism, Weyl semimetals (WSM) exhibit Berry flux monopoles in reciprocal parameter space. As a function of crystal momentum, such monopoles locate at the crossing point of spin-polarized bands forming the Weyl cone. Here, we report momentum-resolved spectroscopic signatures of Berry flux monopoles in TaAs as a paradigmatic WSM. We carried out angle-resolved photoelectron spectroscopy at bulk-sensitive soft X-ray energies (SX-ARPES) combined with photoelectron spin detection and circular dichroism. The experiments reveal large spin- and orbital-angular-momentum (SAM and OAM) polarizations of the Weyl-fermion states, resulting from the broken crystalline inversion symmetry in TaAs. Supported by first-principles calculations, our measurements image signatures of a topologically non-trivial winding of the OAM at the Weyl nodes and unveil a chirality-dependent SAM of the Weyl bands. Our results provide directly bulk-sensitive spectroscopic support for the non-trivial band topology in the WSM TaAs, promising to have profound implications for the study of quantum-geometric effects in solids. Weyl semimetals exhibit Berry flux monopoles in momentum-space, but direct experimental evidence has remained elusive. Here, the authors reveal topologically non-trivial winding of the orbital-angular-momentum at the Weyl nodes and a chirality-dependent spin-angular-momentum of the Weyl bands, as a direct signature of the Berry flux monopoles in TaAs.
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Affiliation(s)
- M Ünzelmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - H Bentmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany.
| | - T Figgemeier
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - P Eck
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - J N Neu
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - B Geldiyev
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - F Diekmann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - S Rohlf
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - J Buck
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - M Hoesch
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - M Kalläne
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - K Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany.,Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - R Thomale
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - T Siegrist
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - G Sangiovanni
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - D Di Sante
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany.,Department of Physics and Astronomy, University of Bologna, Bologna, Italy.,Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA
| | - F Reinert
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
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12
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Tereshchenko OE, Golyashov VA, Rusetsky VS, Mironov AV, Demin AY, Aksenov VV. A new imaging concept in spin polarimetry based on the spin-filter effect. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:864-875. [PMID: 33949994 DOI: 10.1107/s1600577521002307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
The concept of an imaging-type 3D spin detector, based on the combination of spin-exchange interactions in the ferromagnetic (FM) film and spin selectivity of the electron-photon conversion effect in a semiconductor heterostructure, is proposed and demonstrated on a model system. This novel multichannel concept is based on the idea of direct transfer of a 2D spin-polarized electron distribution to image cathodoluminescence (CL). The detector is a hybrid structure consisting of a thin magnetic layer deposited on a semiconductor structure allowing measurement of the spatial and polarization-dependent CL intensity from injected spin-polarized free electrons. The idea is to use spin-dependent electron transmission through in-plane magnetized FM film for in-plane spin detection by measuring the CL intensity from recombined electrons transmitted in the semiconductor. For the incoming electrons with out-of-plane spin polarization, the intensity of circularly polarized CL light can be detected from recombined polarized electrons with holes in the semiconductor. In order to demonstrate the ability of the solid-state spin detector in the image-type mode operation, a spin detector prototype was developed, which consists of a compact proximity focused vacuum tube with a spin-polarized electron source [p-GaAs(Cs,O)], a negative electron affinity (NEA) photocathode and the target [semiconductor heterostructure with quantum wells also with NEA]. The injection of polarized low-energy electrons into the target by varying the kinetic energy in the range 0.5-3.0 eV and up to 1.3 keV was studied in image-type mode. The figure of merit as a function of electron kinetic energy and the target temperature is determined. The spin asymmetry of the CL intensity in a ferromagnetic/semiconductor (FM-SC) junction provides a compact optical method for measuring spin polarization of free-electron beams in image-type mode. The FM-SC detector has the potential for realizing multichannel 3D vectorial reconstruction of spin polarization in momentum microscope and angle-resolved photoelectron spectroscopy systems.
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Affiliation(s)
- Oleg E Tereshchenko
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Vladimir A Golyashov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Vadim S Rusetsky
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
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13
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Vidal RC, Bentmann H, Facio JI, Heider T, Kagerer P, Fornari CI, Peixoto TRF, Figgemeier T, Jung S, Cacho C, Büchner B, van den Brink J, Schneider CM, Plucinski L, Schwier EF, Shimada K, Richter M, Isaeva A, Reinert F. Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi_{4}Te_{7} and MnBi_{6}Te_{10}. PHYSICAL REVIEW LETTERS 2021; 126:176403. [PMID: 33988442 DOI: 10.1103/physrevlett.126.176403] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 01/09/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Using angle-resolved photoelectron spectroscopy (ARPES), we investigate the surface electronic structure of the magnetic van der Waals compounds MnBi_{4}Te_{7} and MnBi_{6}Te_{10}, the n=1 and 2 members of a modular (Bi_{2}Te_{3})_{n}(MnBi_{2}Te_{4}) series, which have attracted recent interest as intrinsic magnetic topological insulators. Combining circular dichroic, spin-resolved and photon-energy-dependent ARPES measurements with calculations based on density functional theory, we unveil complex momentum-dependent orbital and spin textures in the surface electronic structure and disentangle topological from trivial surface bands. We find that the Dirac-cone dispersion of the topologial surface state is strongly perturbed by hybridization with valence-band states for Bi_{2}Te_{3}-terminated surfaces but remains preserved for MnBi_{2}Te_{4}-terminated surfaces. Our results firmly establish the topologically nontrivial nature of these magnetic van der Waals materials and indicate that the possibility of realizing a quantized anomalous Hall conductivity depends on surface termination.
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Affiliation(s)
- R C Vidal
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - H Bentmann
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - J I Facio
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany, EU
| | - T Heider
- Peter Grünberg Institut, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany, EU
| | - P Kagerer
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - C I Fornari
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - T R F Peixoto
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - T Figgemeier
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
| | - S Jung
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
- Department of Physics, Gyeongsang National University, Jinju 52828, Korea
| | - C Cacho
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - B Büchner
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany, EU
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany, EU
| | - J van den Brink
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany, EU
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany, EU
| | - C M Schneider
- Peter Grünberg Institut, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany, EU
| | - L Plucinski
- Peter Grünberg Institut, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany, EU
| | - E F Schwier
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - K Shimada
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - M Richter
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany, EU
- Dresden Center for Computational Materials Science (DCMS), Technische Universität Dresden, D-01062 Dresden, Germany, EU
| | - A Isaeva
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany, EU
- Department of Physics, Gyeongsang National University, Jinju 52828, Korea
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands, EU
| | - F Reinert
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany, EU
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14
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Ahmadov EJ, Aliev ZS, Babanly DM, Imamaliyeva SZ, Gasymov VA, Babanly MB. The Quasi-Ternary System Bi2S3–Bi2Te3–BiI3. RUSS J INORG CHEM+ 2021. [DOI: 10.1134/s0036023621040021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Topological superconductivity in a van der Waals heterostructure. Nature 2020; 588:424-428. [DOI: 10.1038/s41586-020-2989-y] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/23/2020] [Indexed: 11/08/2022]
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16
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Kovács-Krausz Z, Hoque AM, Makk P, Szentpéteri B, Kocsis M, Fülöp B, Yakushev MV, Kuznetsova TV, Tereshchenko OE, Kokh KA, Lukács I, Taniguchi T, Watanabe K, Dash SP, Csonka S. Electrically Controlled Spin Injection from Giant Rashba Spin-Orbit Conductor BiTeBr. NANO LETTERS 2020; 20:4782-4791. [PMID: 32511931 PMCID: PMC7660945 DOI: 10.1021/acs.nanolett.0c00458] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/05/2020] [Indexed: 05/31/2023]
Abstract
Ferromagnetic materials are the widely used source of spin-polarized electrons in spintronic devices, which are controlled by external magnetic fields or spin-transfer torque methods. However, with increasing demand for smaller and faster spintronic components utilization of spin-orbit phenomena provides promising alternatives. New materials with unique spin textures are highly desirable since all-electric creation and control of spin polarization is expected where the strength, as well as an arbitrary orientation of the polarization, can be defined without the use of a magnetic field. In this work, we use a novel spin-orbit crystal BiTeBr for this purpose. Because of its giant Rashba spin splitting, bulk spin polarization is created at room temperature by an electric current. Integrating BiTeBr crystal into graphene-based spin valve devices, we demonstrate for the first time that it acts as a current-controlled spin injector, opening new avenues for future spintronic applications in integrated circuits.
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Affiliation(s)
- Zoltán Kovács-Krausz
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
| | - Anamul Md Hoque
- Department
of Microtechnology and Nanoscience, Chalmers
University of Technology, SE-41296, Göteborg, Sweden
| | - Péter Makk
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
| | - Bálint Szentpéteri
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
| | - Mátyás Kocsis
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
| | - Bálint Fülöp
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
| | - Michael Vasilievich Yakushev
- M.N.
Miheev Institute of Metal Physics, Ural
Branch of the Russian Academy of Science, 620108, Ekaterinburg, Russia
- Ural
Federal University, Ekaterinburg, 620002, Russia
- Institute
of Solid State Chemistry, Ural Branch of
the Russian Academy of Science, Ekaterinburg, 620990, Russia
| | - Tatyana Vladimirovna Kuznetsova
- M.N.
Miheev Institute of Metal Physics, Ural
Branch of the Russian Academy of Science, 620108, Ekaterinburg, Russia
- Ural
Federal University, Ekaterinburg, 620002, Russia
| | - Oleg Evgenevich Tereshchenko
- St.
Petersburg State University, 198504, St. Petersburg, Russia
- A.
V. Rzhanov Institute of Semiconductor Physics, 630090, Novosibirsk, Russia
- Novosibirsk
State University, 630090, Novosibirsk, Russia
| | - Konstantin Aleksandrovich Kokh
- St.
Petersburg State University, 198504, St. Petersburg, Russia
- Novosibirsk
State University, 630090, Novosibirsk, Russia
- V.
S. Sobolev Institute of Geology and Mineralogy, 630090, Novosibirsk, Russia
| | - István
Endre Lukács
- Center
for Energy Research, Institute of Technical
Physics and Material Science, H-1121 Budapest, Hungary
| | - Takashi Taniguchi
- National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Saroj Prasad Dash
- Department
of Microtechnology and Nanoscience, Chalmers
University of Technology, SE-41296, Göteborg, Sweden
| | - Szabolcs Csonka
- Department
of Physics, Budapest University of Technology
and Economics and Nanoelectronics ‘Momentum’ Research
Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
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17
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Rashba-like spin splitting along three momentum directions in trigonal layered PtBi 2. Nat Commun 2019; 10:4765. [PMID: 31628366 PMCID: PMC6802102 DOI: 10.1038/s41467-019-12805-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 09/27/2019] [Indexed: 11/08/2022] Open
Abstract
Spin-orbit coupling (SOC) has gained much attention for its rich physical phenomena and highly promising applications in spintronic devices. The Rashba-type SOC in systems with inversion symmetry breaking is particularly attractive for spintronics applications since it allows for flexible manipulation of spin current by external electric fields. Here, we report the discovery of a giant anisotropic Rashba-like spin splitting along three momentum directions (3D Rashba-like spin splitting) with a helical spin polarization around the M points in the Brillouin zone of trigonal layered PtBi2. Due to its inversion asymmetry and reduced symmetry at the M point, Rashba-type as well as Dresselhaus-type SOC cooperatively yield a 3D spin splitting with αR ≈ 4.36 eV Å in PtBi2. The experimental realization of 3D Rashba-like spin splitting not only has fundamental interests but also paves the way to the future exploration of a new class of material with unprecedented functionalities for spintronics applications. Rashba type spin splitting – relevant for spintronics applications - is driven by inversion symmetry breaking but could so far not be realized in all momentum directions in a crystal. Here, the authors report on PtBi2 that exhibits Rashba spin splitting in all three momentum directions.
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18
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Min CH, Bentmann H, Neu JN, Eck P, Moser S, Figgemeier T, Ünzelmann M, Kissner K, Lutz P, Koch RJ, Jozwiak C, Bostwick A, Rotenberg E, Thomale R, Sangiovanni G, Siegrist T, Di Sante D, Reinert F. Orbital Fingerprint of Topological Fermi Arcs in the Weyl Semimetal TaP. PHYSICAL REVIEW LETTERS 2019; 122:116402. [PMID: 30951331 DOI: 10.1103/physrevlett.122.116402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/19/2018] [Indexed: 06/09/2023]
Abstract
The monopnictides TaAs and TaP are well-established Weyl semimetals. Yet, a precise assignment of Fermi arcs, accommodating the predicted chiral charge of the bulk Weyl points, has been difficult in these systems, and the topological character of different surface features in the Fermi surface is not fully understood. Here, employing a joint analysis from linear dichroism in angle-resolved photoemission and first-principles calculations, we unveil the orbital texture on the full Fermi surface of TaP(001). We observe pronounced switches in the orbital texture at the projected Weyl nodes, and show how they facilitate a topological classification of the surface band structure. Our findings establish a critical role of the orbital degrees of freedom in mediating the surface-bulk connectivity in Weyl semimetals.
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Affiliation(s)
- Chul-Hee Min
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Hendrik Bentmann
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Jennifer N Neu
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - Philipp Eck
- Theoretische Physik I, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Simon Moser
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Tim Figgemeier
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Maximilian Ünzelmann
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Katharina Kissner
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Peter Lutz
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Roland J Koch
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Chris Jozwiak
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Aaron Bostwick
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Ronny Thomale
- Theoretische Physik I, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Giorgio Sangiovanni
- Theoretische Physik I, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Theo Siegrist
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, Florida 32310, USA
| | - Domenico Di Sante
- Theoretische Physik I, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Friedrich Reinert
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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19
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Hsu MC, Yao LZ, Tan SG, Chang CR, Liang G, Jalil MBA. Inherent orbital spin textures in Rashba effect and their implications in spin-orbitronics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:285502. [PMID: 29809165 DOI: 10.1088/1361-648x/aac86f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Rashba effect gives rise to the key feature of chiral spin texture. Recently it was demonstrated that the orbital angular momentum (OAM) texture forms the underlying basis for Rashba spin texture. Here we solve a model Hamiltonian of a generic p-orbital system in the presence of crystal field, internal spin-orbit coupling (SOC) and inversion symmetry breaking (ISB), and demonstrate, in addition to OAM and spin texture, the existence of orbital projection (OP) of the spin texture in a general Rashba system. The unique form of the OP pattern follows from the same condition for the existence of chirality of the spin texture. From the analytical results, we obtained the spin polarization as a function of parameters such as the SOC strength, crystal field splitting and degree of ISB, and compare them with those from numerical solutions and ab initio calculations. All three methods yield highly consistent results. Our results suggest means of external modulation, and elucidate the multi-orbital nature of the Rashba effect and the underlying OP of the spin texture. The understanding has potential applications in fields such as spin-orbitronics that requires delicate control between orbital occupancy and spin momentum.
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Affiliation(s)
- Ming-Chien Hsu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore. Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
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20
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Bentmann H, Maaß H, Krasovskii EE, Peixoto TRF, Seibel C, Leandersson M, Balasubramanian T, Reinert F. Strong Linear Dichroism in Spin-Polarized Photoemission from Spin-Orbit-Coupled Surface States. PHYSICAL REVIEW LETTERS 2017; 119:106401. [PMID: 28949177 DOI: 10.1103/physrevlett.119.106401] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Indexed: 06/07/2023]
Abstract
A comprehensive understanding of spin-polarized photoemission is crucial for accessing the electronic structure of spin-orbit coupled materials. Yet, the impact of the final state in the photoemission process on the photoelectron spin has been difficult to assess in these systems. We present experiments for the spin-orbit split states in a Bi-Ag surface alloy showing that the alteration of the final state with energy may cause a complete reversal of the photoelectron spin polarization. We explain the effect on the basis of ab initio one-step photoemission theory and describe how it originates from linear dichroism in the angular distribution of photoelectrons. Our analysis shows that the modulated photoelectron spin polarization reflects the intrinsic spin density of the surface state being sampled differently depending on the final state, and it indicates linear dichroism as a natural probe of spin-orbit coupling at surfaces.
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Affiliation(s)
- H Bentmann
- Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - H Maaß
- Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - E E Krasovskii
- Departamento de Física de Materiales, Facultad de Ciencias Quíimicas, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Apdo. 1072, San Sebastián/Donostia, 20080 Basque Country, Spain
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, San Sebastián/Donostia, 20018 Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - T R F Peixoto
- Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - C Seibel
- Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - M Leandersson
- MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - T Balasubramanian
- MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - F Reinert
- Experimentelle Physik VII and Röntgen Research Center for Complex Materials (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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21
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Nechaev IA, Eremeev SV, Krasovskii EE, Echenique PM, Chulkov EV. Quantum spin Hall insulators in centrosymmetric thin films composed from topologically trivial BiTeI trilayers. Sci Rep 2017; 7:43666. [PMID: 28252656 PMCID: PMC5333630 DOI: 10.1038/srep43666] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/26/2017] [Indexed: 11/16/2022] Open
Abstract
The quantum spin Hall insulators predicted ten years ago and now experimentally observed are instrumental for a break- through in nanoelectronics due to non-dissipative spin-polarized electron transport through their edges. For this transport to persist at normal conditions, the insulators should possess a sufficiently large band gap in a stable topological phase. Here, we theoretically show that quantum spin Hall insulators can be realized in ultra-thin films constructed from a trivial band insulator with strong spin-orbit coupling. The thinnest film with an inverted gap large enough for practical applications is a centrosymmetric sextuple layer built out of two inversely stacked non-centrosymmetric BiTeI trilayers. This nontrivial sextuple layer turns out to be the structure element of an artificially designed strong three-dimensional topological insulator Bi2Te2I2. We reveal general principles of how a topological insulator can be composed from the structure elements of the BiTeX family (X = I, Br, Cl), which opens new perspectives towards engineering of topological phases.
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Affiliation(s)
- I. A. Nechaev
- Centro de Física de Materiales CFM - MPC and Centro Mixto CSIC-UPV/EHU, 20018 San Sebastián/Donostia, Spain
- Tomsk State University, 634050, Tomsk, Russia
- Saint Petersburg State University, 198504, Saint Petersburg, Russia
| | - S. V. Eremeev
- Tomsk State University, 634050, Tomsk, Russia
- Saint Petersburg State University, 198504, Saint Petersburg, Russia
- Institute of Strength Physics and Materials Science, 634055, Tomsk, Russia
- Donostia International Physics Center, 20018 San Sebastián/Donostia, Spain
| | - E. E. Krasovskii
- Donostia International Physics Center, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales UPV/EHU, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián/Donostia, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
| | - P. M. Echenique
- Donostia International Physics Center, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales UPV/EHU, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián/Donostia, Spain
| | - E. V. Chulkov
- Centro de Física de Materiales CFM - MPC and Centro Mixto CSIC-UPV/EHU, 20018 San Sebastián/Donostia, Spain
- Tomsk State University, 634050, Tomsk, Russia
- Saint Petersburg State University, 198504, Saint Petersburg, Russia
- Donostia International Physics Center, 20018 San Sebastián/Donostia, Spain
- Departamento de Física de Materiales UPV/EHU, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián/Donostia, Spain
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22
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Spin-dependent quantum interference in photoemission process from spin-orbit coupled states. Nat Commun 2017; 8:14588. [PMID: 28232721 PMCID: PMC5333099 DOI: 10.1038/ncomms14588] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/13/2017] [Indexed: 11/26/2022] Open
Abstract
Spin–orbit interaction entangles the orbitals with the different spins. The spin–orbital-entangled states were discovered in surface states of topological insulators. However, the spin–orbital-entanglement is not specialized in the topological surface states. Here, we show the spin–orbital texture in a surface state of Bi(111) by laser-based spin- and angle-resolved photoelectron spectroscopy (laser-SARPES) and describe three-dimensional spin-rotation effect in photoemission resulting from spin-dependent quantum interference. Our model reveals that, in the spin–orbit-coupled systems, the spins pointing to the mutually opposite directions are independently locked to the orbital symmetries. Furthermore, direct detection of coherent spin phenomena by laser-SARPES enables us to clarify the phase of the dipole transition matrix element responsible for the spin direction in photoexcited states. These results permit the tuning of the spin polarization of optically excited electrons in solids with strong spin–orbit interaction. Spin–orbit coupling produces spin–orbital-entanglement in quasiparticle eigenstates. Here, Yaji et al. present a general description of spin–orbital-entangled states and establish a model for dipole transition based on spin-dependent quantum interference, that permits optical spin control.
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23
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Dauth M, Graus M, Schelter I, Wießner M, Schöll A, Reinert F, Kümmel S. Perpendicular Emission, Dichroism, and Energy Dependence in Angle-Resolved Photoemission: The Importance of The Final State. PHYSICAL REVIEW LETTERS 2016; 117:183001. [PMID: 27834988 DOI: 10.1103/physrevlett.117.183001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Indexed: 06/06/2023]
Abstract
Angle-resolved photoemission spectroscopy has been developed to a very high accuracy. However, effects that depend sensitively on the state of the emitted photoelectron were so far hard to compute for real molecules. We here show that the real-time propagation approach to time-dependent density functional theory allows us to obtain final-state effects consistently from first principles and with an accuracy that allows for the interpretation of experimental data. In a combined theoretical and experimental study we demonstrate that the approach captures three hallmark effects that are beyond the final-state plane-wave approximation: emission perpendicular to the light polarization, circular dichroism in the photoelectron angular distribution, and a pronounced energy dependence of the photoemission intensity.
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Affiliation(s)
- M Dauth
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
| | - M Graus
- Experimental Physics VII, University of Würzburg, D-97074 Würzburg, Germany
| | - I Schelter
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
| | - M Wießner
- Experimental Physics VII, University of Würzburg, D-97074 Würzburg, Germany
| | - A Schöll
- Experimental Physics VII, University of Würzburg, D-97074 Würzburg, Germany
| | - F Reinert
- Experimental Physics VII, University of Würzburg, D-97074 Würzburg, Germany
| | - S Kümmel
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
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