1
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Chi Z, Lee S, Yang H, Dolan E, Safeer CK, Ingla-Aynés J, Herling F, Ontoso N, Martín-García B, Gobbi M, Low T, Hueso LE, Casanova F. Control of Charge-Spin Interconversion in van der Waals Heterostructures with Chiral Charge Density Waves. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310768. [PMID: 38237911 DOI: 10.1002/adma.202310768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/10/2023] [Indexed: 01/28/2024]
Abstract
A charge density wave (CDW) represents an exotic state in which electrons are arranged in a long-range ordered pattern in low-dimensional materials. Although the understanding of the fundamental character of CDW is enriched after extensive studies, its practical application remains limited. Here, an unprecedented demonstration of a tunable charge-spin interconversion (CSI) in graphene/1T-TaS2 van der Waals heterostructures is shown by manipulating the distinct CDW phases in 1T-TaS2. Whereas CSI from spins polarized in all three directions is observed in the heterostructure when the CDW phase does not show commensurability, the output of one of the components disappears, and the other two are enhanced when the CDW phase becomes commensurate. The experimental observation is supported by first-principles calculations, which evidence that chiral CDW multidomains in the heterostructure are at the origin of the switching of CSI. The results uncover a new approach for on-demand CSI in low-dimensional systems, paving the way for advanced spin-orbitronic devices.
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Affiliation(s)
- Zhendong Chi
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Seungjun Lee
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Haozhe Yang
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Eoin Dolan
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - C K Safeer
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, UK
| | - Josep Ingla-Aynés
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Franz Herling
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Nerea Ontoso
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Beatriz Martín-García
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48009, Basque Country, Spain
| | - Marco Gobbi
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48009, Basque Country, Spain
- Centro de Física de Materiales (CSIC-EHU/UPV) and Materials Physics Center (MPC), Donostia-San Sebastián, 20018, Basque Country, Spain
| | - Tony Low
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Physics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Luis E Hueso
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48009, Basque Country, Spain
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, Donostia-San Sebastián, 20018, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48009, Basque Country, Spain
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2
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Guo L, Hu S, Gu X, Zhang R, Wang K, Yan W, Sun X. Emerging Spintronic Materials and Functionalities. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2301854. [PMID: 37309258 DOI: 10.1002/adma.202301854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/01/2023] [Indexed: 06/14/2023]
Abstract
The explosive growth of the information era has put forward urgent requirements for ultrahigh-speed and extremely efficient computations. In direct contrary to charge-based computations, spintronics aims to use spins as information carriers for data storage, transmission, and decoding, to help fully realize electronic device miniaturization and high integration for next-generation computing technologies. Currently, many novel spintronic materials have been developed with unique properties and multifunctionalities, including organic semiconductors (OSCs), organic-inorganic hybrid perovskites (OIHPs), and 2D materials (2DMs). These materials are useful to fulfill the demand for developing diverse and advanced spintronic devices. Herein, these promising materials are systematically reviewed for advanced spintronic applications. Due to the distinct chemical and physical structures of OSCs, OIHPs, and 2DMs, their spintronic properties (spin transport and spin manipulation) are discussed separately. In addition, some multifunctionalities due to photoelectric and chiral-induced spin selectivity (CISS) are overviewed, including the spin-filter effect, spin-photovoltaics, spin-light emitting devices, and spin-transistor functions. Subsequently, challenges and future perspectives of using these multifunctional materials for the development of advanced spintronics are presented.
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Affiliation(s)
- Lidan Guo
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Shunhua Hu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xianrong Gu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Rui Zhang
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Kai Wang
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, P. R. China
| | - Wenjing Yan
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG9 2RD, UK
| | - Xiangnan Sun
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- School of Material Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
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3
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Cao L, Chen Q, Zhu Y, Tong K, Li W, Ma J, Jalali M, Huang Z, Wu J, Zhai Y. Interfacial Modulation of Spin-Orbit Torques Induced by Two-Dimensional van der Waals Material ZrSe 3. ACS APPLIED MATERIALS & INTERFACES 2024; 16:19764-19770. [PMID: 38577833 DOI: 10.1021/acsami.4c00881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Two-dimensional van der Waals (2D vdW) materials are widely used in spin-orbit torque (SOT) devices. Recent studies have demonstrated the low crystal symmetry and large spin Hall conductivity of 2D vdW ZrSe3, indicating its potential applications in low-power SOT devices. Here, we study the interfacial contribution of SOTs and current-induced magnetization switching in the ZrSe3/Py (Ni80Fe20) and ZrSe3/Cu/Py heterostructures. SOT efficiencies of samples are detected by the spin-torque ferromagnetic resonance (ST-FMR), and out-of-plane damping-like torque (τB) is observed. The ratio between τB and the field-like torque (τA) decreases from 0.175 to 0.138 when inserting 1 nm Cu at the interface and then drops to 0.001 when the thickness of Cu intercalation is 2 nm, indicating that Cu intercalation inhibits the τB component of SOT. Moreover, the SOT efficiency is increased from 3.05 to 5.21, which may be attributed to the Cu intercalation being beneficial to improve the interface between Py and ZrSe3. Theoretical calculation has shown that the Cu spacer can change the conductivity of ZrSe3 from semiconductor to conductor, thereby decreasing the Schottky barrier and increasing the transmission efficiency of the spin current. Furthermore, magneto-optical Kerr effect (MOKE) microscopy is employed to verify the current-driven magnetization switching in these structures. In comparison to the ZrSe3/Py bilayer, the critical current density of ZrSe3/Cu/Py is reduced when inserting 1 nm Cu, demonstrating the higher SOT efficiency and lower power consumption in ZrSe3/Cu/Py structures.
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Affiliation(s)
- Lulu Cao
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
| | - Qian Chen
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
| | - Yonghui Zhu
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
| | - Kaiyu Tong
- Department of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom
| | - Wenjia Li
- Department of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom
| | - Jun Ma
- Department of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom
| | - Milad Jalali
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
| | - Zhaocong Huang
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
| | - Jing Wu
- Department of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom
| | - Ya Zhai
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, Jiangsu 211189, People's Republic of China
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4
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Zhang Y, Xu H, Jia K, Lan G, Huang Z, He B, He C, Shao Q, Wang Y, Zhao M, Ma T, Dong J, Guo C, Cheng C, Feng J, Wan C, Wei H, Shi Y, Zhang G, Han X, Yu G. Room temperature field-free switching of perpendicular magnetization through spin-orbit torque originating from low-symmetry type II Weyl semimetal. SCIENCE ADVANCES 2023; 9:eadg9819. [PMID: 37910619 PMCID: PMC10619928 DOI: 10.1126/sciadv.adg9819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023]
Abstract
Spin-orbit torque (SOT) is a promising strategy to deterministically switch the perpendicular magnetization, but usually requires an in-plane magnetic field for breaking the mirror symmetry, which is not suitable for most advanced industrial applications. Van der Waals (vdW) materials with low crystalline symmetry and topological band structures, e.g., Weyl semimetals (WSMs), potentially serve as an outstanding system that may simultaneously realize field-free switching and high energy efficiency. Yet, the demonstration of these superiorities at room temperature has not been realized. Here, we achieve a field-free switching of perpendicular magnetization by using a layered type II WSM, TaIrTe4, in a TaIrTe4/Ti/CoFeB system at room temperature with the critical switching current density ~2.4 × 106 A cm-2. The field-free switching is ascribed to the out-of-plane SOT allowed by the low crystal symmetry. Our work suggests that using low-symmetry materials to generate SOT is a promising route for the manipulation of perpendicular magnetization at room temperature.
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Affiliation(s)
- Yu Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongjun Xu
- 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
| | - Ke Jia
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guibin Lan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiheng Huang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bin He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Congli He
- Institute of Advanced Materials, Beijing Normal University, Beijing 100875, China
| | - Qiming Shao
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yizhan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingkun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tianyi Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Dong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenyang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Cheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiafeng Feng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Caihua Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Hongxiang Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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5
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Zhu L. Switching of Perpendicular Magnetization by Spin-Orbit Torque. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300853. [PMID: 37004142 DOI: 10.1002/adma.202300853] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Magnetic materials with strong perpendicular magnetic anisotropy are of great interest for the development of nonvolatile magnetic memory and computing technologies due to their high stabilities at the nanoscale. However, electrical switching of such perpendicular magnetization in an energy-efficient, deterministic, scalable manner has remained a big challenge. This problem has recently attracted enormous efforts in the field of spintronics. Here, recent advances and challenges in the understanding of the electrical generation of spin currents, the switching mechanisms and the switching strategies of perpendicular magnetization, the switching current density by spin-orbit torque of transverse spins, the choice of perpendicular magnetic materials are reviewed, and the progress in prototype perpendicular SOT memory and logic devices toward the goal of energy-efficient, dense, fast perpendicular spin-orbit torque applications is summarized.
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Affiliation(s)
- Lijun Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
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6
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Yang H, Ormaza M, Chi Z, Dolan E, Ingla-Aynés J, Safeer CK, Herling F, Ontoso N, Gobbi M, Martín-García B, Schiller F, Hueso LE, Casanova F. Gate-Tunable Spin Hall Effect in an All-Light-Element Heterostructure: Graphene with Copper Oxide. NANO LETTERS 2023; 23:4406-4414. [PMID: 37140909 DOI: 10.1021/acs.nanolett.3c00687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Graphene is a light material for long-distance spin transport due to its low spin-orbit coupling, which at the same time is the main drawback for exhibiting a sizable spin Hall effect. Decoration by light atoms has been predicted to enhance the spin Hall angle in graphene while retaining a long spin diffusion length. Here, we combine a light metal oxide (oxidized Cu) with graphene to induce the spin Hall effect. Its efficiency, given by the product of the spin Hall angle and the spin diffusion length, can be tuned with the Fermi level position, exhibiting a maximum (1.8 ± 0.6 nm at 100 K) around the charge neutrality point. This all-light-element heterostructure shows a larger efficiency than conventional spin Hall materials. The gate-tunable spin Hall effect is observed up to room temperature. Our experimental demonstration provides an efficient spin-to-charge conversion system free from heavy metals and compatible with large-scale fabrication.
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Affiliation(s)
- Haozhe Yang
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Maider Ormaza
- Departamento de Polímeros y Materiales Avanzados: Física Química y Tecnología Facultad de Químicas, UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
| | - Zhendong Chi
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Eoin Dolan
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Josep Ingla-Aynés
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - C K Safeer
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Franz Herling
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Nerea Ontoso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Marco Gobbi
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
- Centro de Física de Materiales (CSIC-EHU/UPV) and Materials Physics Center (MPC), 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Beatriz Martín-García
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
| | - Frederik Schiller
- Centro de Física de Materiales (CSIC-EHU/UPV) and Materials Physics Center (MPC), 20018 Donostia-San Sebastian, Basque Country, Spain
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Luis E Hueso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Basque Country, Spain
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7
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Dednam W, García-Blázquez MA, Zotti LA, Lombardi EB, Sabater C, Pakdel S, Palacios JJ. A Group-Theoretic Approach to the Origin of Chirality-Induced Spin-Selectivity in Nonmagnetic Molecular Junctions. ACS NANO 2023; 17:6452-6465. [PMID: 36947721 PMCID: PMC10100547 DOI: 10.1021/acsnano.2c11410] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Spin-orbit coupling gives rise to a range of spin-charge interconversion phenomena in nonmagnetic systems where certain spatial symmetries are reduced or absent. Chirality-induced spin-selectivity (CISS), a term that generically refers to a spin-dependent electron transfer in nonmagnetic chiral systems, is one such case, appearing in a variety of seemingly unrelated situations ranging from inorganic materials to molecular devices. In particular, the origin of CISS in molecular junctions is a matter of an intense current debate. Here, we derive a set of geometrical conditions for this effect to appear, hinting at the fundamental role of symmetries beyond otherwise relevant quantitative issues. Our approach, which draws on the use of point-group symmetries within the scattering formalism for transport, shows that electrode symmetries are as important as those of the molecule when it comes to the emergence of a spin-polarization and, by extension, to the possible appearance of CISS. It turns out that standalone metallic nanocontacts can exhibit spin-polarization when relative rotations which reduce the symmetry are introduced. As a corollary, molecular junctions with achiral molecules can also exhibit spin-polarization along the direction of transport, provided that the whole junction is chiral in a specific way. This formalism also allows the prediction of qualitative changes of the spin-polarization upon substitution of a chiral molecule in the junction with its enantiomeric partner. Quantum transport calculations based on density functional theory corroborate all of our predictions and provide further quantitative insight within the single-particle framework.
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Affiliation(s)
- W. Dednam
- Department
of Physics, Florida Science Campus, University
of South Africa, 1710 Johannesburg, South Africa
| | - M. A. García-Blázquez
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Linda A. Zotti
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autonoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - E. B. Lombardi
- Department
of Physics, Florida Science Campus, University
of South Africa, 1710 Johannesburg, South Africa
| | - C. Sabater
- Departamento
de Física Aplicada and Unidad asociada CSIC, Universidad de Alicante, E-03690 Alicante, Spain
| | - S. Pakdel
- CAMD, Department
of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - J. J. Palacios
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Instituto
Nicolás Cabrera (INC) and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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8
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Wang L, Xiong J, Cheng B, Dai Y, Wang F, Pan C, Cao T, Liu X, Wang P, Chen M, Yan S, Liu Z, Xiao J, Xu X, Wang Z, Shi Y, Cheong SW, Zhang H, Liang SJ, Miao F. Cascadable in-memory computing based on symmetric writing and readout. SCIENCE ADVANCES 2022; 8:eabq6833. [PMID: 36490344 DOI: 10.1126/sciadv.abq6833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The building block of in-memory computing with spintronic devices is mainly based on the magnetic tunnel junction with perpendicular interfacial anisotropy (p-MTJ). The resulting asymmetric write and readout operations impose challenges in downscaling and direct cascadability of p-MTJ devices. Here, we propose that a previously unimplemented symmetric write and readout mechanism can be realized in perpendicular-anisotropy spin-orbit (PASO) quantum materials based on Fe3GeTe2 and WTe2. We demonstrate that field-free and deterministic reversal of the perpendicular magnetization can be achieved using unconventional charge-to-z-spin conversion. The resulting magnetic state can be readily probed with its intrinsic inverse process, i.e., z-spin-to-charge conversion. Using the PASO quantum material as a fundamental building block, we implement the functionally complete set of logic-in-memory operations and a more complex nonvolatile half-adder logic function. Our work highlights the potential of PASO quantum materials for the development of scalable energy-efficient and ultrafast spintronic computing.
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Affiliation(s)
- Lizheng Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Junlin Xiong
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Bin Cheng
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yudi Dai
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Fuyi Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chen Pan
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Tianjun Cao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaowei Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Pengfei Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Moyu Chen
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shengnan Yan
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zenglin Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jingjing Xiao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xianghan Xu
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhenlin Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Youguo Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Sang-Wook Cheong
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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9
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Noh S, Choe D, Jin H, Yoo JW. Enhancement of the Rashba Effect in a Conducting SrTiO 3 Surface by MoO 3 Capping. ACS APPLIED MATERIALS & INTERFACES 2022; 14:50280-50287. [PMID: 36282511 DOI: 10.1021/acsami.2c11840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Systems having inherent structural asymmetry retain the Rashba-type spin-orbit interaction, which ties the spin and momentum of electrons in the band structure, leading to coupled spin and charge transport. One of the electrical manifestations of the Rashba spin-orbit interaction is nonreciprocal charge transport, which could be utilized for rectifying devices. Further tuning of the Rashba spin-orbit interaction allows additional functionalities in spin-orbitronic applications. In this work, we present our study of nonreciprocal charge transport in a conducting SrTiO3 (001) surface and its significant enhancement by a capping layer. The conductive strontium titanate SrTiO3 (STO) (001) surface was created through oxygen vacancies by Ar+ irradiation, and the nonreciprocal signal was probed by angle- and magnetic field-dependent second harmonic voltage measurement with an AC current. We observed robust directional transport in the Ar+-irradiated sample at low temperatures. The magnitude of the nonreciprocal signal is highly dependent on the irradiation time as it affects the depth of the conducting layer and the impact of the topmost conducting layer. Moreover, the nonreciprocal resistance was significantly enhanced by simply adding a MoO3 capping layer on the conductive STO surface. These results show a simple methodology for tuning and investigating the Rashba effect in a conductive STO surface, which could be adopted for various two-dimensional (2D) conducting layers for spin-orbitronic applications.
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Affiliation(s)
- Seunghyeon Noh
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Korea
| | - Daeseong Choe
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Korea
| | - Hosub Jin
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan44919, Korea
| | - Jung-Woo Yoo
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Korea
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10
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Berry curvature-induced local spin polarisation in gated graphene/WTe2 heterostructures. Nat Commun 2022; 13:3152. [PMID: 35672292 PMCID: PMC9174237 DOI: 10.1038/s41467-022-30744-3] [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: 04/26/2021] [Accepted: 05/16/2022] [Indexed: 11/16/2022] Open
Abstract
Experimental control of local spin-charge interconversion is of primary interest for spintronics. Van der Waals (vdW) heterostructures combining graphene with a strongly spin-orbit coupled two-dimensional (2D) material enable such functionality by design. Electric spin valve experiments have thus far provided global information on such devices, while leaving the local interplay between symmetry breaking, charge flow across the heterointerface and aspects of topology unexplored. Here, we probe the gate-tunable local spin polarisation in current-driven graphene/WTe2 heterostructures through magneto-optical Kerr microscopy. Even for a nominal in-plane transport, substantial out-of-plane spin accumulation is induced by a corresponding out-of-plane current flow. We present a theoretical model which fully explains the gate- and bias-dependent onset and spatial distribution of the intense Kerr signal as a result of a non-linear anomalous Hall effect in the heterostructure, which is enabled by its reduced point group symmetry. Our findings unravel the potential of 2D heterostructure engineering for harnessing topological phenomena for spintronics, and constitute an important step toward nanoscale, electrical spin control. Spin-based electronics offers significantly improved efficiency, but a major challenge is the electric manipulation of spin. Here, Powalla et al find a large gate induced spinpolarization in graphene/WTe2 heterostructures, illustrating the potential of such heterostructures for spintronics.
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11
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Calavalle F, Suárez-Rodríguez M, Martín-García B, Johansson A, Vaz DC, Yang H, Maznichenko IV, Ostanin S, Mateo-Alonso A, Chuvilin A, Mertig I, Gobbi M, Casanova F, Hueso LE. Gate-tuneable and chirality-dependent charge-to-spin conversion in tellurium nanowires. NATURE MATERIALS 2022; 21:526-532. [PMID: 35256792 DOI: 10.1038/s41563-022-01211-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Chiral materials are an ideal playground for exploring the relation between symmetry, relativistic effects and electronic transport. For instance, chiral organic molecules have been intensively studied to electrically generate spin-polarized currents in the last decade, but their poor electronic conductivity limits their potential for applications. Conversely, chiral inorganic materials such as tellurium have excellent electrical conductivity, but their potential for enabling the electrical control of spin polarization in devices remains unclear. Here, we demonstrate the all-electrical generation, manipulation and detection of spin polarization in chiral single-crystalline tellurium nanowires. By recording a large (up to 7%) and chirality-dependent unidirectional magnetoresistance, we show that the orientation of the electrically generated spin polarization is determined by the nanowire handedness and uniquely follows the current direction, while its magnitude can be manipulated by an electrostatic gate. Our results pave the way for the development of magnet-free chirality-based spintronic devices.
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Affiliation(s)
| | | | | | - Annika Johansson
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
- Max Planck Institute of Microstructure Physics, Halle, Germany
| | - Diogo C Vaz
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Haozhe Yang
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Igor V Maznichenko
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Sergey Ostanin
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Aurelio Mateo-Alonso
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- POLYMAT, University of the Basque Country UPV/EHU, Donostia-San Sebastian, Spain
| | - Andrey Chuvilin
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Ingrid Mertig
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Marco Gobbi
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
- Centro de Física de Materiales CSIC-UPV/EHU, Donostia-San Sebastian, Spain.
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| | - Luis E Hueso
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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12
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Chen Q, Liang J, Fang B, Zhu Y, Wang J, Lv W, Lv W, Cai J, Huang Z, Zhai Y, Zhang B, Zeng Z. Proximity effect of a two-dimensional van der Waals magnet Fe 3GeTe 2 on nickel films. NANOSCALE 2021; 13:14688-14693. [PMID: 34533556 DOI: 10.1039/d1nr03342e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent advances in two-dimensional van der Waals (2D vdW) magnets provide new platforms to study their magnetism in reduced dimensions. However, most of the studies performed to date have been limited to low temperatures. Here, we report the proximity effect of a 2D vdW magnet Fe3GeTe2 (FGT) on nickel (Ni) films at room temperature. Ferromagnetic resonance measurements show that FGT can increase the perpendicular magnetic anisotropy (PMA) and magnetic damping of the adjacent Ni film. Such an interfacial effect is observed at room temperature, and becomes more pronounced as the temperature decreases. A similar effect is also achieved in another 2D heterostructure of Cr2Ge2Te6/Ni, implying its universality in a variety of 2D magnetic materials. Our work provides a new approach for utilizing 2D magnets in spintronics at room temperature.
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Affiliation(s)
- Qian Chen
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Jian Liang
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Bin Fang
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Yonghui Zhu
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Jiachen Wang
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Weiming Lv
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Wenxing Lv
- Physics Laboratory, Industrial Training Center, Shenzhen Polytechnic, Shenzhen, Guangdong, 518055, China
| | - Jialin Cai
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
- Nanchang Nano-Devices and Technologies Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Nanchang, Jiangxi, 330200, China
| | - Zhaocong Huang
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Ya Zhai
- School of Physics, Southeast University, Nanjing, Jiangsu, 211189, China.
| | - Baoshun Zhang
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
| | - Zhongming Zeng
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
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13
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Tang W, Liu H, Li Z, Pan A, Zeng Y. Spin-Orbit Torque in Van der Waals-Layered Materials and Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100847. [PMID: 34323390 PMCID: PMC8456225 DOI: 10.1002/advs.202100847] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Spin-orbit torque (SOT) opens an efficient and versatile avenue for the electrical manipulation of magnetization in spintronic devices. The enhancement of SOT efficiency and reduction of power consumption are key points for the implementation of high-performance SOT devices, which strongly rely on the spin-orbit coupling (SOC) strength and magnetic properties of ferromagnetic/non-magnetic heterostructures. Recently, van der Waals-layered materials have shown appealing properties for use in efficient SOT applications. On the one hand, transition-metal dichalcogenides, topological insulators, and graphene-based heterostructures possess appreciable SOC strength. This feature can efficiently converse the charge current into spin current and result in large SOT. On the other hand, the newly discovered layered magnetic materials provide ultra-thin and gate-tunable ferromagnetic candidates for high-performance SOT devices. In this review, the latest advancements of SOT research in various layered materials are summarized. First, a brief introduction of SOT is given. Second, SOT studies of various layered materials and heterostructures are summarized. Subsequently, progresses on SOT-induced magnetization switching are presented. Finally, current challenges and prospects for future development are suggested.
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Affiliation(s)
- Wei Tang
- Key laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
| | - Haoliang Liu
- State Key Laboratory on Tunable Laser TechnologyMinistry of Industry and Information Technology Key Lab of Micro‐Nano Optoelectronic Information SystemSchool of ScienceHarbin Institute of TechnologyShenzhen518055China
| | - Zhe Li
- State Key Laboratory on Tunable Laser TechnologyMinistry of Industry and Information Technology Key Lab of Micro‐Nano Optoelectronic Information SystemSchool of ScienceHarbin Institute of TechnologyShenzhen518055China
| | - Anlian Pan
- Key Laboratory for Micro‐Nano Physics and Technology of Hunan ProvinceCollege of Materials Science and EngineeringHunan UniversityChangsha410082China
| | - Yu‐Jia Zeng
- Key laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
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14
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Deng Y, Zhao X, Zhu C, Li P, Duan R, Liu G, Liu Z. MoTe 2: Semiconductor or Semimetal? ACS NANO 2021; 15:12465-12474. [PMID: 34379388 DOI: 10.1021/acsnano.1c01816] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transition metal tellurides (TMTs) have attracted intense interest due to their intriguing physical properties arising from their diverse phase topologies. To date, a wide range of physical properties have been discovered for TMTs, including that they can act as topological insulators, semiconductors, Weyl semimetals, and superconductors. Among the TMT families, MoTe2 is a representative material because of its Janus nature and rich phases. In this Perspective, we first introduce phase structures in monolayer and bulk MoTe2 and then summarize MoTe2 synthesis strategies. We highlight recent advances of Janus MoTe2 in terms of material structures and emerging quantum states. We also provide insight into the opportunities and challenges faced by MoTe2-associated device design and applications.
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Affiliation(s)
- Ya Deng
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Chao Zhu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ruihuan Duan
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Guangtong Liu
- 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
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, 637553 Singapore
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15
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Sierra JF, Fabian J, Kawakami RK, Roche S, Valenzuela SO. Van der Waals heterostructures for spintronics and opto-spintronics. NATURE NANOTECHNOLOGY 2021; 16:856-868. [PMID: 34282312 DOI: 10.1038/s41565-021-00936-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The large variety of 2D materials and their co-integration in van der Waals heterostructures enable innovative device engineering. In addition, their atomically thin nature promotes the design of artificial materials by proximity effects that originate from short-range interactions. Such a designer approach is particularly compelling for spintronics, which typically harnesses functionalities from thin layers of magnetic and non-magnetic materials and the interfaces between them. Here we provide an overview of recent progress in 2D spintronics and opto-spintronics using van der Waals heterostructures. After an introduction to the forefront of spin transport research, we highlight the unique spin-related phenomena arising from spin-orbit and magnetic proximity effects. We further describe the ability to create multifunctional hybrid heterostructures based on van der Waals materials, combining spin, valley and excitonic degrees of freedom. We end with an outlook on perspectives and challenges for the design and production of ultracompact all-2D spin devices and their potential applications in conventional and quantum technologies.
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Affiliation(s)
- Juan F Sierra
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
| | - Jaroslav Fabian
- Institute for Theoretical Physics, University of Regensburg, Regensburg, Germany
| | | | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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16
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Pace S, Martini L, Convertino D, Keum DH, Forti S, Pezzini S, Fabbri F, Mišeikis V, Coletti C. Synthesis of Large-Scale Monolayer 1T'-MoTe 2 and Its Stabilization via Scalable hBN Encapsulation. ACS NANO 2021; 15:4213-4225. [PMID: 33605730 PMCID: PMC8023802 DOI: 10.1021/acsnano.0c05936] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 02/02/2021] [Indexed: 06/02/2023]
Abstract
Out of the different structural phases of molybdenum ditelluride (MoTe2), the distorted octahedral 1T' possesses great interest for fundamental physics and is a promising candidate for the implementation of innovative devices such as topological transistors. Indeed, 1T'-MoTe2 is a semimetal with superconductivity, which has been predicted to be a Weyl semimetal and a quantum spin Hall insulator in bulk and monolayer form, respectively. Large instability of monolayer 1T'-MoTe2 in environmental conditions, however, has made its investigation extremely challenging so far. In this work, we demonstrate homogeneous growth of large single-crystal (up to 500 μm) monolayer 1T'-MoTe2 via chemical vapor deposition (CVD) and its stabilization in air with a scalable encapsulation approach. The encapsulant is obtained by electrochemically delaminating CVD hexagonal boron nitride (hBN) from copper foil, and it is applied on the freshly grown 1T'-MoTe2 via a top-down dry lamination step. The structural and electrical properties of encapsulated 1T'-MoTe2 have been monitored over several months to assess the degree of degradation of the material. We find that when encapsulated with hBN, the lifetime of monolayer 1T'-MoTe2 successfully increases from a few minutes to more than a month. Furthermore, the encapsulated monolayer can be subjected to transfer, device processing, and heating and cooling cycles without degradation of its properties. The potential of this scalable heterostack is confirmed by the observation of signatures of low-temperature phase transition in monolayer 1T'-MoTe2 by both Raman spectroscopy and electrical measurements. The growth and encapsulation methods reported in this work can be employed for further fundamental studies of this enticing material as well as facilitate the technological development of monolayer 1T'-MoTe2.
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Affiliation(s)
- Simona Pace
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Leonardo Martini
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Domenica Convertino
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Dong Hoon Keum
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Stiven Forti
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Sergio Pezzini
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Filippo Fabbri
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Vaidotas Mišeikis
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Camilla Coletti
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
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17
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Shao Q, Li P, Liu L, Yang H, Fukami S, Razavi A, Wu H, Wang K, Freimuth F, Mokrousov Y, Stiles MD, Emori S, Hoffmann A, Åkerman J, Roy K, Wang JP, Yang SH, Garello K, Zhang W. Roadmap of spin-orbit torques. IEEE TRANSACTIONS ON MAGNETICS 2021; 57:10.48550/arXiv.2104.11459. [PMID: 37057056 PMCID: PMC10091395 DOI: 10.48550/arxiv.2104.11459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Spin-orbit torque (SOT) is an emerging technology that enables the efficient manipulation of spintronic devices. The initial processes of interest in SOTs involved electric fields, spin-orbit coupling, conduction electron spins and magnetization. More recently interest has grown to include a variety of other processes that include phonons, magnons, or heat. Over the past decade, many materials have been explored to achieve a larger SOT efficiency. Recently, holistic design to maximize the performance of SOT devices has extended material research from a nonmagnetic layer to a magnetic layer. The rapid development of SOT has spurred a variety of SOT-based applications. In this Roadmap paper, we first review the theories of SOTs by introducing the various mechanisms thought to generate or control SOTs, such as the spin Hall effect, the Rashba-Edelstein effect, the orbital Hall effect, thermal gradients, magnons, and strain effects. Then, we discuss the materials that enable these effects, including metals, metallic alloys, topological insulators, two-dimensional materials, and complex oxides. We also discuss the important roles in SOT devices of different types of magnetic layers, such as magnetic insulators, antiferromagnets, and ferrimagnets. Afterward, we discuss device applications utilizing SOTs. We discuss and compare three-terminal and two-terminal SOT-magnetoresistive random-access memories (MRAMs); we mention various schemes to eliminate the need for an external field. We provide technological application considerations for SOT-MRAM and give perspectives on SOT-based neuromorphic devices and circuits. In addition to SOT-MRAM, we present SOT-based spintronic terahertz generators, nano-oscillators, and domain wall and skyrmion racetrack memories. This paper aims to achieve a comprehensive review of SOT theory, materials, and applications, guiding future SOT development in both the academic and industrial sectors.
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Affiliation(s)
- Qiming Shao
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University
| | - Luqiao Liu
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore
| | - Shunsuke Fukami
- Research Institute of Electrical Communication, Tohoku University
| | - Armin Razavi
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | - Hao Wu
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | - Kang Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | | | | | - Mark D Stiles
- Alternative Computing Group, National Institute of Standards and Technology
| | | | - Axel Hoffmann
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign
| | | | - Kaushik Roy
- Department of Electrical and Computer Engineering, Purdue University
| | - Jian-Ping Wang
- Electrical and Computer Engineering Department, University of Minnesota
| | | | - Kevin Garello
- IMEC, Leuven, Belgium; CEA-Spintec, Grenoble, France
| | - Wei Zhang
- Physics Department, Oakland University
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18
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Garcia JH, Vila M, Hsu CH, Waintal X, Pereira VM, Roche S. Canted Persistent Spin Texture and Quantum Spin Hall Effect in WTe_{2}. PHYSICAL REVIEW LETTERS 2020; 125:256603. [PMID: 33416383 DOI: 10.1103/physrevlett.125.256603] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/02/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
We report an unconventional quantum spin Hall phase in the monolayer WTe_{2}, which exhibits hitherto unknown features in other topological materials. The low symmetry of the structure induces a canted spin texture in the yz plane, which dictates the spin polarization of topologically protected boundary states. Additionally, the spin Hall conductivity gets quantized (2e^{2}/h) with a spin quantization axis parallel to the canting direction. These findings are based on large-scale quantum simulations of the spin Hall conductivity tensor and nonlocal resistances in multiprobe geometries using a realistic tight-binding model elaborated from first-principle methods. The observation of this canted quantum spin Hall effect, related to the formation of topological edge states with nontrivial spin polarization, demands for specific experimental design and suggests interesting alternatives for manipulating spin information in topological materials.
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Affiliation(s)
- Jose H Garcia
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Marc Vila
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Department of Physics, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Chuang-Han Hsu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Xavier Waintal
- Université Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France
| | - Vitor M Pereira
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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19
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Liang S, Shi S, Hsu CH, Cai K, Wang Y, He P, Wu Y, Pereira VM, Yang H. Spin-Orbit Torque Magnetization Switching in MoTe 2 /Permalloy Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002799. [PMID: 32743908 DOI: 10.1002/adma.202002799] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/29/2020] [Indexed: 05/27/2023]
Abstract
The ability to switch magnetic elements by spin-orbit-induced torques has recently attracted much attention for a path toward high-performance, nonvolatile memories with low power consumption. Realizing efficient spin-orbit-based switching requires the harnessing of both new materials and novel physics to obtain high charge-to-spin conversion efficiencies, thus making the choice of spin source crucial. Here, the observation of spin-orbit torque switching in bilayers consisting of a semimetallic film of 1T'-MoTe2 adjacent to permalloy is reported. Deterministic switching is achieved without external magnetic fields at room temperature, and the switching occurs with currents one order of magnitude smaller than those typical in devices using the best-performing heavy metals. The thickness-dependence can be understood if the interfacial spin-orbit contribution is considered in addition to the bulk spin Hall effect. Further threefold reduction in the switching current is demonstrated with resort to dumbbell-shaped magnetic elements. These findings foretell exciting prospects of using MoTe2 for low-power semimetal-material-based spin devices.
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Affiliation(s)
- Shiheng Liang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
- Faculty of Physics and Electronic Science, Hubei University, Wuhan, 430062, P. R. China
| | - Shuyuan Shi
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Chuang-Han Hsu
- Department of Physics, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore
| | - Kaiming Cai
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Yi Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Pan He
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Yang Wu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Vitor M Pereira
- Department of Physics, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, 117546, Singapore
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20
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Zhao B, Karpiak B, Khokhriakov D, Johansson A, Hoque AM, Xu X, Jiang Y, Mertig I, Dash SP. Unconventional Charge-Spin Conversion in Weyl-Semimetal WTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000818. [PMID: 32776352 DOI: 10.1002/adma.202000818] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/08/2020] [Indexed: 05/17/2023]
Abstract
An outstanding feature of topological quantum materials is their novel spin topology in the electronic band structures with an expected large charge-to-spin conversion efficiency. Here, a charge-current-induced spin polarization in the type-II Weyl semimetal candidate WTe2 and efficient spin injection and detection in a graphene channel up to room temperature are reported. Contrary to the conventional spin Hall and Rashba-Edelstein effects, the measurements indicate an unconventional charge-to-spin conversion in WTe2 , which is primarily forbidden by the crystal symmetry of the system. Such a large spin polarization can be possible in WTe2 due to a reduced crystal symmetry combined with its large spin Berry curvature, spin-orbit interaction with a novel spin-texture of the Fermi states. A robust and practical method is demonstrated for electrical creation and detection of such a spin polarization using both charge-to-spin conversion and its inverse phenomenon and utilized it for efficient spin injection and detection in the graphene channel up to room temperature. These findings open opportunities for utilizing topological Weyl materials as nonmagnetic spin sources in all-electrical van der Waals spintronic circuits and for low-power and high-performance nonvolatile spintronic technologies.
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Affiliation(s)
- Bing Zhao
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Bogdan Karpiak
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Dmitrii Khokhriakov
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Annika Johansson
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, 06099, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle, 06120, Germany
| | - Anamul Md Hoque
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
| | - Xiaoguang Xu
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yong Jiang
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Ingrid Mertig
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, 06099, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle, 06120, Germany
| | - Saroj P Dash
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, SE-41296, Sweden
- Graphene Center, Chalmers University of Technology, Göteborg, SE-41296, Sweden
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21
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Liu Y, Shao Q. Two-Dimensional Materials for Energy-Efficient Spin-Orbit Torque Devices. ACS NANO 2020; 14:9389-9407. [PMID: 32692151 DOI: 10.1021/acsnano.0c04403] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Spin-orbit torques (SOTs), which rely on spin current generation from charge current in a nonmagnetic material, promise an energy-efficient scheme for manipulating magnetization in magnetic devices. A critical topic for spintronic devices using SOTs is to enhance the charge to spin conversion efficiency. Besides, the current-induced spin polarization is usually limited to in-plane, whereas out-of-plane spin polarization could be favored for efficient perpendicular magnetization switching. Recent advances in utilizing two important classes of two-dimensional materials-topological insulators and transition-metal dichalcogenides-as spin sources to generate SOT shed light on addressing these challenges. Topological insulators such as bismuth selenide have shown a giant SOT efficiency, which is larger than those from three-dimensional heavy metals by at least 1 order of magnitude. Transition-metal dichalcogenides such as tungsten telluride have shown a current-induced out-of-plane spin polarization, which is allowed by the reduced symmetry. In this review, we use symmetry arguments to predict and analyze SOTs in two-dimensional material-based heterostructures. We summarize the recent progress of SOT studies based on topological insulators and transition-metal dichalcogenides and show how these results are in line with the symmetry arguments. At last, we identify unsolved issues in the current studies and suggest three potential research directions in this field.
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Affiliation(s)
- Yuting Liu
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Qiming Shao
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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22
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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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23
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Safeer CK, Ingla-Aynés J, Ontoso N, Herling F, Yan W, Hueso LE, Casanova F. Spin Hall Effect in Bilayer Graphene Combined with an Insulator up to Room Temperature. NANO LETTERS 2020; 20:4573-4579. [PMID: 32406693 DOI: 10.1021/acs.nanolett.0c01428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Spin-orbit coupling in graphene can be enhanced by chemical functionalization, adatom decoration, or proximity with a van der Waals material. As it is expected that such enhancement gives rise to a sizable spin Hall effect, a spin-to-charge current conversion phenomenon of technological relevance, it has sparked wide research interest. However, it has only been measured in graphene/transition-metal dichalcogenide van der Waals heterostructures with limited scalability. Here, we experimentally demonstrate the spin Hall effect up to room temperature in graphene combined with a nonmagnetic insulator, an evaporated bismuth oxide layer. The measured spin Hall effect arises most likely from an extrinsic mechanism. With a large spin-to-charge conversion efficiency, scalability, and ease of integration to electronic devices, we show a promising material heterostructure suitable for spin-based device applications.
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Affiliation(s)
- C K Safeer
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Josep Ingla-Aynés
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Nerea Ontoso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Franz Herling
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
| | - Wenjing Yan
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, U.K
| | - Luis E Hueso
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
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