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Guo J, Zhang J, Di Y, Gan Z. Research Progress on Rashba Effect in Two-Dimensional Organic-Inorganic Hybrid Lead Halide Perovskites. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:683. [PMID: 38668177 PMCID: PMC11054462 DOI: 10.3390/nano14080683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/09/2024] [Accepted: 04/13/2024] [Indexed: 04/29/2024]
Abstract
The Rashba effect appears in the semiconductors with an inversion-asymmetric structure and strong spin-orbit coupling, which splits the spin-degenerated band into two sub-bands with opposite spin states. The Rashba effect can not only be used to regulate carrier relaxations, thereby improving the performance of photoelectric devices, but also used to expand the applications of semiconductors in spintronics. In this mini-review, recent research progress on the Rashba effect of two-dimensional (2D) organic-inorganic hybrid perovskites is summarized. The origin and magnitude of Rashba spin splitting, layer-dependent Rashba band splitting of 2D perovskites, the Rashba effect in 2D perovskite quantum dots, a 2D/3D perovskite composite, and 2D-perovskites-based van der Waals heterostructures are discussed. Moreover, applications of the 2D Rashba effect in circularly polarized light detection are reviewed. Finally, future research to modulate the Rashba strength in 2D perovskites is prospected, which is conceived to promote the optoelectronic and spintronic applications of 2D perovskites.
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Affiliation(s)
- Junhong Guo
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Wenyuan Road 9, Nanjing 210023, China;
| | - Jinlei Zhang
- School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China;
| | - Yunsong Di
- Center for Future Optoelectronic Functional Materials, School of Computer and Electronic Information, Nanjing Normal University, Nanjing 210023, China
| | - Zhixing Gan
- Center for Future Optoelectronic Functional Materials, School of Computer and Electronic Information, Nanjing Normal University, Nanjing 210023, China
- College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
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2
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Pan R, Tang X, Kan L, Li Y, Yu H, Wang K. Spin-photogalvanic effect in chiral lead halide perovskites. NANOSCALE 2023; 15:3300-3308. [PMID: 36723152 DOI: 10.1039/d2nr06919a] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Low-temperature solution-made chiral lead halide perovskites (LHPs) have spontaneous Bychkov-Rashba spin orbit coupling (SOC) and chiral-induced spin selectivity (CISS) qualities. Their coexistence may give rise to considerable spin and charge conversion capabilities for spin-orbitronic applications. In this study, we demonstrate the spin-photogalvanic effect for (R-MBA)2PbI4 and (S-MBA)2PbI4 polycrystalline film-based lateral devices (100 μm channel length). The light helicity dependence of the short-circuit photocurrent exhibits the circular photogalvanic effect (CPGE) and linear photogalvanic effect (LPGE) with decent two-fold symmetry for a complete cycle in a wide temperature range from 4 K to 300 K. Because of the Rashba SOC and the material helicity, the effect is converse for the two chiral LHPs. In addition, its magnitude and sign can be effectively tuned by constant magnetic fields. The Rashba effect, CISS-generated unbalanced spin transport, and chiral-induced magnetization are mutually responsible for it. Our study evidently proves the future prospect of using chiral LHPs for spin-orbitronics.
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Affiliation(s)
- Ruiheng Pan
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
| | - Xiantong Tang
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
| | - Lixuan Kan
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing, 100044, China.
- Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Yang Li
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing, 100044, China.
- Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Haomiao Yu
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing, 100044, China.
- Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Kai Wang
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing, 100044, China.
- Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, China
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3
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Tsikritzis D, Chatzimanolis K, Tzoganakis N, Bellani S, Zappia MI, Bianca G, Curreli N, Buha J, Kriegel I, Antonatos N, Sofer Z, Krassas M, Rogdakis K, Bonaccorso F, Kymakis E. Two-dimensional BiTeI as a novel perovskite additive for printable perovskite solar cells. SUSTAINABLE ENERGY & FUELS 2022; 6:5345-5359. [PMID: 36776412 PMCID: PMC9907396 DOI: 10.1039/d2se01109c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/14/2022] [Indexed: 06/18/2023]
Abstract
Hybrid organic-inorganic perovskite solar cells (PSCs) are attractive printable, flexible, and cost-effective optoelectronic devices constituting an alternative technology to conventional Si-based ones. The incorporation of low-dimensional materials, such as two-dimensional (2D) materials, into the PSC structure is a promising route for interfacial and bulk perovskite engineering, paving the way for improved power conversion efficiency (PCE) and long-term stability. In this work, we investigate the incorporation of 2D bismuth telluride iodide (BiTeI) flakes as additives in the perovskite active layer, demonstrating their role in tuning the interfacial energy-level alignment for optimum device performance. By varying the concentration of BiTeI flakes in the perovskite precursor solution between 0.008 mg mL-1 and 0.1 mg mL-1, a downward shift in the energy levels of the perovskite results in an optimal alignment of the energy levels of the materials across the cell structure, as supported by device simulations. Thus, the cell fill factor (FF) increases with additive concentration, reaching values greater than 82%, although the suppression of open circuit voltage (V oc) is reported beyond an additive concentration threshold of 0.03 mg mL-1. The most performant devices delivered a PCE of 18.3%, with an average PCE showing a +8% increase compared to the reference devices. This work demonstrates the potential of 2D-material-based additives for the engineering of PSCs via energy level optimization at perovskite/charge transporting layer interfaces.
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Affiliation(s)
- Dimitris Tsikritzis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
- Institute of Emerging Technologies (i-EMERGE) of HMU Research Center Heraklion 71410 Crete Greece
| | - Konstantinos Chatzimanolis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
| | - Nikolaos Tzoganakis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
| | | | | | - Gabriele Bianca
- Graphene Labs, Istituto Italiano di Tecnologia via Morego, 30 16163 Genova Italy
| | - Nicola Curreli
- Functional Nanosystems, Istituto Italiano di Tecnologia via Morego, 30 16163 Genova Italy
| | - Joka Buha
- BeDimensional S.p.A. Via Lungotorrente Secca 30R 16163 Genova Italy
- Department of Nanochemistry, Istituto Italiano di Tecnologia via Morego, 30 16163 Genova 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 Prague 6 16628 Czech Republic
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague Technická 5 Prague 6 16628 Czech Republic
| | - Miron Krassas
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
| | - Konstantinos Rogdakis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
- Institute of Emerging Technologies (i-EMERGE) of HMU Research Center Heraklion 71410 Crete Greece
| | - Francesco Bonaccorso
- BeDimensional S.p.A. Via Lungotorrente Secca 30R 16163 Genova Italy
- Graphene Labs, Istituto Italiano di Tecnologia via Morego, 30 16163 Genova Italy
| | - Emmanuel Kymakis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University (HMU) Heraklion 71410 Crete Greece
- Institute of Emerging Technologies (i-EMERGE) of HMU Research Center Heraklion 71410 Crete Greece
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4
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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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5
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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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6
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Xie YM, Gao XJ, Xu XY, Zhang CP, Hu JX, Gao JZ, Law KT. Kramers nodal line metals. Nat Commun 2021; 12:3064. [PMID: 34031382 PMCID: PMC8144424 DOI: 10.1038/s41467-021-22903-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/06/2021] [Indexed: 11/09/2022] Open
Abstract
Recently, it was pointed out that all chiral crystals with spin-orbit coupling (SOC) can be Kramers Weyl semimetals (KWSs) which possess Weyl points pinned at time-reversal invariant momenta. In this work, we show that all achiral non-centrosymmetric materials with SOC can be a new class of topological materials, which we term Kramers nodal line metals (KNLMs). In KNLMs, there are doubly degenerate lines, which we call Kramers nodal lines (KNLs), connecting time-reversal invariant momenta. The KNLs create two types of Fermi surfaces, namely, the spindle torus type and the octdong type. Interestingly, all the electrons on octdong Fermi surfaces are described by two-dimensional massless Dirac Hamiltonians. These materials support quantized optical conductance in thin films. We further show that KNLMs can be regarded as parent states of KWSs. Therefore, we conclude that all non-centrosymmetric metals with SOC are topological, as they can be either KWSs or KNLMs.
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Affiliation(s)
- Ying-Ming Xie
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Xue-Jian Gao
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiao Yan Xu
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Cheng-Ping Zhang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jin-Xin Hu
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jason Z Gao
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - K T Law
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China.
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7
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Liu X, Chanana A, Huynh U, Xue F, Haney P, Blair S, Jiang X, Vardeny ZV. Circular photogalvanic spectroscopy of Rashba splitting in 2D hybrid organic-inorganic perovskite multiple quantum wells. Nat Commun 2020; 11:323. [PMID: 31949152 PMCID: PMC6965620 DOI: 10.1038/s41467-019-14073-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 12/10/2019] [Indexed: 11/23/2022] Open
Abstract
The two-dimensional (2D) Ruddlesden−Popper organic-inorganic halide perovskites such as (2D)-phenethylammonium lead iodide (2D-PEPI) have layered structure that resembles multiple quantum wells (MQW). The heavy atoms in 2D-PEPI contribute a large spin-orbit coupling that influences the electronic band structure. Upon breaking the inversion symmetry, a spin splitting (‘Rashba splitting’) occurs in the electronic bands. We have studied the spin splitting in 2D-PEPI single crystals using the circular photogalvanic effect (CPGE). We confirm the existence of Rashba splitting at the electronic band extrema of 35±10 meV, and identify the main inversion symmetry breaking direction perpendicular to the MQW planes. The CPGE action spectrum above the bandgap reveals spin-polarized photocurrent generated by ultrafast relaxation of excited photocarriers separated in momentum space. Whereas the helicity dependent photocurrent with below-gap excitation is due to spin-galvanic effect of the ionized spin-polarized excitons, where spin polarization occurs in the spin-split bands due to asymmetric spin-flip. Hybrid organic-inorganic perovskites (HOIP) have high potential for spintronics applications. Using the circular photogalvanic effect the authors demonstrate the existence of Rashba-splitting in the continuum bands of a 2D layered HOIP that results from inversion symmetry breaking along the growth direction.
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Affiliation(s)
- Xiaojie Liu
- Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, 84112, USA
| | - Ashish Chanana
- Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, 84112, USA.,Department of Electrical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Uyen Huynh
- Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, 84112, USA
| | - Fei Xue
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Institute for Research in Electronics and Applied Physics & Maryland Nanocenter, University of Maryland, College Park, MD, 20742, USA
| | - Paul Haney
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Steve Blair
- Department of Electrical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Xiaomei Jiang
- Department of Physics, University of South Florida, Tampa, FL, 33620, USA.
| | - Z V Vardeny
- Department of Physics & Astronomy, University of Utah, Salt Lake City, UT, 84112, USA.
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8
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Wlaźlak E, Blachecki A, Bisztyga-Szklarz M, Klejna S, Mazur T, Mech K, Pilarczyk K, Przyczyna D, Suchecki M, Zawal P, Szaciłowski K. Heavy pnictogen chalcohalides: the synthesis, structure and properties of these rediscovered semiconductors. Chem Commun (Camb) 2018; 54:12133-12162. [DOI: 10.1039/c8cc05149f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Heavy pnictogen chalcohalides offer various shades from the same palette, like “Paysage” by Nicolas de Staël. Their versatility and tunability lead to a new world of possible applications.
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Affiliation(s)
- Ewelina Wlaźlak
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
- Jagiellonian University
- Faculty of Chemistry
| | - Andrzej Blachecki
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
- AGH University of Science and Technology, Faculty of Non-Ferrous Metals
- 30-059 Krakow
| | - Magdalena Bisztyga-Szklarz
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
| | - Sylwia Klejna
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
| | - Tomasz Mazur
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
| | - Krzysztof Mech
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
| | - Kacper Pilarczyk
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
| | - Dawid Przyczyna
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science
- 30-059 Krakow
| | - Maciej Suchecki
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science
- 30-059 Krakow
| | - Piotr Zawal
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science
- 30-059 Krakow
| | - Konrad Szaciłowski
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology
- 30-059 Krakow
- Poland
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9
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Bahramy MS, Ogawa N. Bulk Rashba Semiconductors and Related Quantum Phenomena. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1605911. [PMID: 28370556 DOI: 10.1002/adma.201605911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/15/2017] [Indexed: 06/07/2023]
Abstract
Bithmuth tellurohalides BiTeX (X = Cl, Br and I) are model examples of bulk Rashba semiconductors, exhibiting a giant Rashba-type spin splitting among their both valence and conduction bands. Extensive spectroscopic and transport experiments combined with the state-of-the-art first-principles calculations have revealed many unique quantum phenomena emerging from the bulk Rashba effect in these systems. The novel features such as the exotic inter- and intra-band optical transitions, enhanced magneto-optical response, divergent orbital dia-/para-magnetic susceptibility and helical spin textures with a nontrivial Berry's phase in the momentum space are among the salient discoveries, all arising from this effect. Also, it is theoretically proposed and indications have been experimentally reported that bulk Rashba semiconductors such as BiTeI have the capability of becoming a topological insulator under the application of a hydrostatic pressure. Here, we overview these studies and show that BiTeX are an ideal platform to explore the next aspects of quantum matter, which could ultimately be utilized to create spintronic devices with novel functionalities.
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Affiliation(s)
- Mohammad Saeed Bahramy
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan
| | - Naoki Ogawa
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
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10
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Butler CJ, Yang PY, Sankar R, Lien YN, Lu CI, Chang LY, Chen CH, Wei CM, Chou FC, Lin MT. Quasiparticle Scattering in the Rashba Semiconductor BiTeBr: The Roles of Spin and Defect Lattice Site. ACS NANO 2016; 10:9361-9369. [PMID: 27660852 DOI: 10.1021/acsnano.6b04109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Observations of quasiparticle interference have been used in recent years to examine exotic carrier behavior at the surfaces of emergent materials, connecting carrier dispersion and scattering dynamics to real-space features with atomic resolution. We observe quasiparticle interference in the strongly Rashba split 2DEG-like surface band found at the tellurium termination of BiTeBr and examine two mechanisms governing quasiparticle scattering: We confirm the suppression of spin-flip scattering by comparing measured quasiparticle interference with a spin-dependent elastic scattering model applied to the calculated spectral function. We also use atomically resolved STM maps to identify point defect lattice sites and spectro-microscopy imaging to discern their varying scattering strengths, which we understand in terms of the calculated orbital characteristics of the surface band. Defects on the Bi sublattice cause the strongest scattering of the predominantly Bi 6p derived surface band, with other defects causing nearly no scattering near the conduction band minimum.
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Affiliation(s)
| | | | | | | | | | - Luo-Yueh Chang
- National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan
| | - Chia-Hao Chen
- National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan
| | | | - Fang-Cheng Chou
- National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan
- Taiwan Consortium of Emergent Crystalline Materials (TCECM), National Science Council , Taipei 10622, Taiwan
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11
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Liebmann M, Rinaldi C, Di Sante D, Kellner J, Pauly C, Wang RN, Boschker JE, Giussani A, Bertoli S, Cantoni M, Baldrati L, Asa M, Vobornik I, Panaccione G, Marchenko D, Sánchez-Barriga J, Rader O, Calarco R, Picozzi S, Bertacco R, Morgenstern M. Giant Rashba-Type Spin Splitting in Ferroelectric GeTe(111). ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:560-565. [PMID: 26599640 DOI: 10.1002/adma.201503459] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/02/2015] [Indexed: 06/05/2023]
Abstract
Photoelectron spectroscopy in combination with piezoforce microscopy reveals that the helicity of Rashba bands is coupled to the nonvolatile ferroelectric polarization of GeTe(111). A novel surface Rashba band is found and fingerprints of a bulk Rashba band are identified by comparison with density functional theory calculations.
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Affiliation(s)
- Marcus Liebmann
- II. Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074, Aachen, Germany
| | - Christian Rinaldi
- Dipartimento di Fisica, Politecnico di Milano and IFN-CNR, Via Colombo 81, 20133, Milano, Italy
| | - Domenico Di Sante
- Consiglio Nazionale delle Ricerche CNR-SPIN, UOS L'Aquila, Via Vetoio 10, 67100, L'Aquila, Italy
- Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio 10, 67100, L'Aquila, Italy
| | - Jens Kellner
- II. Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074, Aachen, Germany
| | - Christian Pauly
- II. Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074, Aachen, Germany
| | - Rui Ning Wang
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Jos Emiel Boschker
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Alessandro Giussani
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Stefano Bertoli
- Dipartimento di Fisica, Politechnico di Milano, Via Colombo 81, 20133, Milano, Italy
| | - Matteo Cantoni
- Dipartimento di Fisica, Politechnico di Milano, Via Colombo 81, 20133, Milano, Italy
| | - Lorenzo Baldrati
- Dipartimento di Fisica, Politechnico di Milano, Via Colombo 81, 20133, Milano, Italy
| | - Marco Asa
- Dipartimento di Fisica, Politechnico di Milano, Via Colombo 81, 20133, Milano, Italy
| | - Ivana Vobornik
- Consiglio Nazionale delle Ricerche, CNR - IOM, Laboratorio TASC, 34149, Trieste, Italy
| | - Giancarlo Panaccione
- Consiglio Nazionale delle Ricerche, CNR - IOM, Laboratorio TASC, 34149, Trieste, Italy
| | - Dmitry Marchenko
- Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Jaime Sánchez-Barriga
- Helmholtz-Zentrum für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489, Berlin, Germany
| | - Oliver Rader
- Helmholtz-Zentrum für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489, Berlin, Germany
| | - Raffaella Calarco
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Silvia Picozzi
- Consiglio Nazionale delle Ricerche CNR-SPIN, UOS L'Aquila, Via Vetoio 10, 67100, L'Aquila, Italy
| | - Riccardo Bertacco
- Dipartimento di Fisica, Politecnico di Milano and IFN-CNR, Via Colombo 81, 20133, Milano, Italy
| | - Markus Morgenstern
- II. Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074, Aachen, Germany
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12
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Wang J, Lee K, Kovnir K. Synthesis, crystal and electronic structure, and optical properties of two new chalcogenide-iodides: Ba3Q4I2 (Q = S, Se). Inorg Chem Front 2016. [DOI: 10.1039/c5qi00225g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new ternary chalcogenide-iodides, Ba3S4I2 and Ba3Se4I2, exhibit both covalent and ionic chemical bonding.
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Affiliation(s)
- Jian Wang
- Department of Chemistry
- University of California
- Davis
- Davis
- USA
| | - Kathleen Lee
- Department of Chemistry
- University of California
- Davis
- Davis
- USA
| | - Kirill Kovnir
- Department of Chemistry
- University of California
- Davis
- Davis
- USA
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13
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Tunable ferroelectric polarization and its interplay with spin-orbit coupling in tin iodide perovskites. Nat Commun 2014; 5:5900. [PMID: 25533044 DOI: 10.1038/ncomms6900] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/19/2014] [Indexed: 12/22/2022] Open
Abstract
Ferroelectricity is a potentially crucial issue in halide perovskites, breakthrough materials in photovoltaic research. Using density functional theory simulations and symmetry analysis, we show that the lead-free perovskite iodide (FA)SnI3, containing the planar formamidinium cation FA, (NH2CHNH2)(+), is ferroelectric. In fact, the perpendicular arrangement of FA planes, leading to a 'weak' polarization, is energetically more stable than parallel arrangements of FA planes, being either antiferroelectric or 'strong' ferroelectric. Moreover, we show that the 'weak' and 'strong' ferroelectric states with the polar axis along different crystallographic directions are energetically competing. Therefore, at least at low temperatures, an electric field could stabilize different states with the polarization rotated by π/4, resulting in a highly tunable ferroelectricity appealing for multistate logic. Intriguingly, the relatively strong spin-orbit coupling in noncentrosymmetric (FA)SnI3 gives rise to a co-existence of Rashba and Dresselhaus effects and to a spin texture that can be induced, tuned and switched by an electric field controlling the ferroelectric state.
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14
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Butler CJ, Yang HH, Hong JY, Hsu SH, Sankar R, Lu CI, Lu HY, Yang KHO, Shiu HW, Chen CH, Kaun CC, Shu GJ, Chou FC, Lin MT. Mapping polarization induced surface band bending on the Rashba semiconductor BiTeI. Nat Commun 2014; 5:4066. [PMID: 24898943 PMCID: PMC4059917 DOI: 10.1038/ncomms5066] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 05/07/2014] [Indexed: 11/09/2022] Open
Abstract
Surfaces of semiconductors with strong spin-orbit coupling are of great interest for use in spintronic devices exploiting the Rashba effect. BiTeI features large Rashba-type spin splitting in both valence and conduction bands. Either can be shifted towards the Fermi level by surface band bending induced by the two possible polar terminations, making Rashba spin-split electron or hole bands electronically accessible. Here we demonstrate the first real-space microscopic identification of each termination with a multi-technique experimental approach. Using spatially resolved tunnelling spectroscopy across the lateral boundary between the two terminations, a previously speculated on p-n junction-like discontinuity in electronic structure at the lateral boundary is confirmed experimentally. These findings realize an important step towards the exploitation of the unique behaviour of the Rashba semiconductor BiTeI for new device concepts in spintronics.
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Affiliation(s)
| | - Hung-Hsiang Yang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Jhen-Yong Hong
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Shih-Hao Hsu
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Raman Sankar
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Chun-I Lu
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Hsin-Yu Lu
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Kui-Hon Ou Yang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Hung-Wei Shiu
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chia-Hao Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chao-Cheng Kaun
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Guo-Jiun Shu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Fang-Cheng Chou
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Taiwan Consortium of Emergent Crystalline Materials (TCECM), National Science Council, Taipei 10622, Taiwan
| | - Minn-Tsong Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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15
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Tran MK, Levallois J, Lerch P, Teyssier J, Kuzmenko AB, Autès G, Yazyev OV, Ubaldini A, Giannini E, van der Marel D, Akrap A. Infrared- and Raman-spectroscopy measurements of a transition in the crystal structure and a closing of the energy gap of BiTeI under pressure. PHYSICAL REVIEW LETTERS 2014; 112:047402. [PMID: 24580490 DOI: 10.1103/physrevlett.112.047402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Indexed: 06/03/2023]
Abstract
BiTeI is a giant Rashba spin splitting system, in which a noncentrosymmetric topological phase has recently been suggested to appear under high pressure. We investigated the optical properties of this compound, reflectivity and transmission, under pressures up to 15 GPa. The gap feature in the optical conductivity vanishes above p∼9 GPa and does not reappear up to at least 15 GPa. The plasma edge, associated with intrinsically doped charge carriers, is smeared out through a phase transition at 9 GPa. Using high-pressure Raman spectroscopy, we follow the vibrational modes of BiTeI, providing additional clear evidence that the transition at 9 GPa involves a change of crystal structure. This change of crystal structure possibly inhibits the high-pressure topological phase from occurring.
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Affiliation(s)
- M K Tran
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - J Levallois
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - P Lerch
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - J Teyssier
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - A B Kuzmenko
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - G Autès
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - O V Yazyev
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - A Ubaldini
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - E Giannini
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - D van der Marel
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - A Akrap
- Département de la Matière Condensée, University of Geneva, CH-1211 Geneva 4, Switzerland
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16
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Murakawa H, Bahramy MS, Tokunaga M, Kohama Y, Bell C, Kaneko Y, Nagaosa N, Hwang HY, Tokura Y. Detection of Berry's Phase in a Bulk Rashba Semiconductor. Science 2013; 342:1490-3. [DOI: 10.1126/science.1242247] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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17
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Bordács S, Checkelsky JG, Murakawa H, Hwang HY, Tokura Y. Landau level spectroscopy of Dirac electrons in a polar semiconductor with giant Rashba spin splitting. PHYSICAL REVIEW LETTERS 2013; 111:166403. [PMID: 24182286 DOI: 10.1103/physrevlett.111.166403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Indexed: 06/02/2023]
Abstract
Optical excitations of BiTeI with large Rashba spin splitting have been studied in an external magnetic field (B) applied parallel to the polar axis. A sequence of transitions between the Landau levels (LLs), whose energies are in proportion to √B were observed, being characteristic of massless Dirac electrons. The large separation energy between the LLs makes it possible to detect the strongest cyclotron resonance even at room temperature in moderate fields. Unlike in 2D Dirac systems, the magnetic field induced rearrangement of the conductivity spectrum is directly observed.
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Affiliation(s)
- Sándor Bordács
- Quantum Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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18
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Xi X, Ma C, Liu Z, Chen Z, Ku W, Berger H, Martin C, Tanner DB, Carr GL. Signatures of a pressure-induced topological quantum phase transition in BiTeI. PHYSICAL REVIEW LETTERS 2013; 111:155701. [PMID: 24160613 DOI: 10.1103/physrevlett.111.155701] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 06/15/2013] [Indexed: 06/02/2023]
Abstract
We report the observation of two signatures of a pressure-induced topological quantum phase transition in the polar semiconductor BiTeI using x-ray powder diffraction and infrared spectroscopy. The x-ray data confirm that BiTeI remains in its ambient-pressure structure up to 8 GPa. The lattice parameter ratio c/a shows a minimum between 2.0-2.9 GPa, indicating an enhanced c-axis bonding through p(z) band crossing as expected during the transition. Over the same pressure range, the infrared spectra reveal a maximum in the optical spectral weight of the charge carriers, reflecting the closing and reopening of the semiconducting band gap. Both of these features are characteristics of a topological quantum phase transition and are consistent with a recent theoretical proposal.
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Affiliation(s)
- Xiaoxiang Xi
- Photon Sciences, Brookhaven National Laboratory, Upton, New York 11973, USA
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19
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Sakano M, Bahramy MS, Katayama A, Shimojima T, Murakawa H, Kaneko Y, Malaeb W, Shin S, Ono K, Kumigashira H, Arita R, Nagaosa N, Hwang HY, Tokura Y, Ishizaka K. Strongly spin-orbit coupled two-dimensional electron gas emerging near the surface of polar semiconductors. PHYSICAL REVIEW LETTERS 2013; 110:107204. [PMID: 23521291 DOI: 10.1103/physrevlett.110.107204] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Indexed: 06/01/2023]
Abstract
We investigate the two-dimensional highly spin-polarized electron accumulation layers commonly appearing near the surface of n-type polar semiconductors BiTeX (X=I, Br, and Cl) by angular-resolved photoemission spectroscopy. Because of the polarity and the strong spin-orbit interaction built in the bulk atomic configurations, the quantized conduction-band subbands show giant Rashba-type spin splitting. The characteristic 2D confinement effect is clearly observed also in the valence bands down to the binding energy of 4 eV. The X-dependent Rashba spin-orbit coupling is directly estimated from the observed spin-split subbands, which roughly scales with the inverse of the band-gap size in BiTeX.
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Affiliation(s)
- M Sakano
- Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
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20
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Demkó L, Schober GAH, Kocsis V, Bahramy MS, Murakawa H, Lee JS, Kézsmárki I, Arita R, Nagaosa N, Tokura Y. Enhanced infrared magneto-optical response of the nonmagnetic semiconductor BiTeI driven by bulk Rashba splitting. PHYSICAL REVIEW LETTERS 2012; 109:167401. [PMID: 23215127 DOI: 10.1103/physrevlett.109.167401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Indexed: 06/01/2023]
Abstract
We study the magneto-optical (MO) response of the polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3 T). Our first-principles calculations show that the enhanced MO response of BiTeI comes mainly from the intraband transitions between the Rashba-split bulk conduction bands. These transitions connecting electronic states with opposite spin directions become active due to the presence of strong spin-orbit interaction and give rise to distinct features in the MO spectra with a systematic doping dependence. We predict an even more pronounced enhancement in the low-energy MO response and dc Hall effect near the crossing (Dirac) point of the conduction bands.
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Affiliation(s)
- L Demkó
- Multiferroics Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), c/o Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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21
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Landolt G, Eremeev SV, Koroteev YM, Slomski B, Muff S, Neupert T, Kobayashi M, Strocov VN, Schmitt T, Aliev ZS, Babanly MB, Amiraslanov IR, Chulkov EV, Osterwalder J, Dil JH. Disentanglement of surface and bulk Rashba spin splittings in noncentrosymmetric BiTeI. PHYSICAL REVIEW LETTERS 2012; 109:116403. [PMID: 23005655 DOI: 10.1103/physrevlett.109.116403] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Indexed: 06/01/2023]
Abstract
BiTeI has a layered and noncentrosymmetric structure where strong spin-orbit interaction leads to a giant Rashba spin splitting in the bulk bands. We present direct measurements of the bulk band structure obtained with soft x-ray angle-resolved photoemission (ARPES), revealing the three-dimensional Fermi surface. The observed spindle torus shape bears the potential for a topological transition in the bulk by hole doping. Moreover, the bulk electronic structure is clearly disentangled from the two-dimensional surface electronic structure by means of high-resolution and spin-resolved ARPES measurements in the ultraviolet regime. All findings are supported by ab initio calculations.
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Affiliation(s)
- Gabriel Landolt
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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22
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Schober GAH, Murakawa H, Bahramy MS, Arita R, Kaneko Y, Tokura Y, Nagaosa N. Mechanisms of enhanced orbital dia- and paramagnetism: application to the Rashba semiconductor BiTeI. PHYSICAL REVIEW LETTERS 2012; 108:247208. [PMID: 23004320 DOI: 10.1103/physrevlett.108.247208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Indexed: 06/01/2023]
Abstract
We study the magnetic susceptibility of a layered semiconductor BiTeI with giant Rashba spin splitting both theoretically and experimentally to explore its orbital magnetism. Apart from the core contributions, a large temperature-dependent diamagnetic susceptibility is observed when the Fermi energy E(F) is near the crossing point of the Rashba spin-split conduction bands at the time-reversal symmetry point A. On the other hand, when E(F) is below this band crossing, the susceptibility turns to be paramagnetic. These features are consistent with first-principles calculations, which also predict an enhanced orbital magnetic susceptibility with both positive and negative signs as a function of E(F) due to band (anti)crossings. Based on these observations, we propose two mechanisms for the enhanced paramagnetic orbital susceptibility.
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Affiliation(s)
- G A H Schober
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
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23
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Eremeev SV, Nechaev IA, Koroteev YM, Echenique PM, Chulkov EV. Ideal two-dimensional electron systems with a giant Rashba-type spin splitting in real materials: surfaces of bismuth tellurohalides. PHYSICAL REVIEW LETTERS 2012; 108:246802. [PMID: 23004307 DOI: 10.1103/physrevlett.108.246802] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Indexed: 06/01/2023]
Abstract
Spintronics is aimed at actively controlling and manipulating the spin degrees of freedom in semiconductor devices. A promising way to achieve this goal is to make use of the tunable Rashba effect that relies on the spin-orbit interaction in a two-dimensional electron system immersed in an inversion-asymmetric environment. The spin-orbit-induced spin splitting of the two-dimensional electron state provides a basis for many theoretically proposed spintronic devices. However, the lack of semiconductors with large Rashba effect hinders realization of these devices in actual practice. Here we report on a giant Rashba-type spin splitting in two-dimensional electron systems that reside at tellurium-terminated surfaces of bismuth tellurohalides. Among these semiconductors, BiTeCl stands out for its isotropic metallic surface-state band with the Γ-point energy lying deep inside the bulk band gap. The giant spin splitting of this band ensures a substantial spin asymmetry of the inelastic mean free path of quasiparticles with different spin orientations.
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Affiliation(s)
- S V Eremeev
- Institute of Strength Physics and Materials Science, 634021, Tomsk, Russia
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