scholarly journals Anomalous spin Hall and inverse spin Hall effects in magnetic systems

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
X. R. Wang
Keyword(s):  
Hall Effect ◽  
Order Parameter ◽  
Spin Current ◽  
Spin Hall Effect ◽  
Magnetic Systems ◽  
Charge Current ◽  
Spin Currents ◽  
Tensor Quantity ◽  
Hall Effects ◽  
Spin Hall Effects

AbstractSpin current is a very important tensor quantity in spintronics. However, the well-known spin-Hall effect (SHE) can only generate a few of its components whose propagating and polarization directions are perpendicular with each other and to an applied charge current. It is highly desirable in applications to generate spin currents whose polarization can be in any possible direction. Here anomalous SHE and inverse spin-Hall effect (ISHE) in magnetic systems are predicted. Spin currents, whose polarisation and propagation are collinear or orthogonal with each other and along or perpendicular to the charge current, can be generated, depending on whether the applied charge current is along or perpendicular to the order parameter. In anomalous ISHEs, charge currents proportional to the order parameter can be along or perpendicular to the propagating or polarization directions of the spin current.

INTRINSIC SPIN HALL EFFECT IN MESOSCOPIC SYSTEMS

2006 ◽  
Vol 20 (17) ◽  
pp. 2339-2358 ◽  
Author(s):  
L. SHENG ◽  
C. S. TING
Keyword(s):  
Green’S Function ◽  
Hall Effect ◽  
Numerical Method ◽  
Green's Function ◽  
Theoretical Aspect ◽  
Spin Hall Effect ◽  
Function Approach ◽  
Mesoscopic Systems ◽  
Hall Effects ◽  
Spin Hall Effects

The intrinsic spin Hall effect has been attracting increasing theoretical and experimental interest since its discovery about two years ago. In this article, we review the main achievements in the theoretical aspect of both dissipative and nondissipative spin Hall effects in mesoscopic systems. The Landauer–Büttiker formula and Green's function approach based numerical method for the spin Hall effect is also introduced.

scholarly journals Different types of spin currents in the comprehensive materials database of nonmagnetic spin Hall effect

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yang Zhang ◽  
Qiunan Xu ◽  
Klaus Koepernik ◽  
Roman Rezaev ◽  
Oleg Janson ◽  
...  
Keyword(s):  
Hall Effect ◽  
Mirror Symmetry ◽  
Spin Current ◽  
Strong Relationship ◽  
Nodal Line ◽  
Spin Hall Effect ◽  
Spin Currents ◽  
Different Types ◽  
Symmetry Protected ◽  
Crystalline Symmetry

AbstractSpin Hall effect (SHE) has its special position in spintronics. To gain new insight into SHE and to identify materials with substantial spin Hall conductivity (SHC), we performed high-precision high-throughput ab initio calculations of the intrinsic SHC for over 20,000 nonmagnetic crystals. The calculations revealed a strong relationship between the magnitude of the SHC and the crystalline symmetry, where a large SHC is typically associated with mirror symmetry-protected nodal line band structures. This database includes 11 materials with an SHC comparable to or even larger than that of Pt. Materials with different types of spin currents were additionally identified. Furthermore, we found that different types of spin current can be obtained by rotating applied electrical fields. This improves our understanding and is expected to facilitate the design of new types of spin-orbitronic devices.

scholarly journals Observation of the crossover between metallic and insulating regimes of the spin Hall effect

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Hiroyuki Moriya ◽  
Akira Musha ◽  
Satoshi Haku ◽  
Kazuya Ando
Keyword(s):  
Hall Effect ◽  
Condensed Matter ◽  
Spin Hall Effect ◽  
Large Collection ◽  
Universal Scaling ◽  
Berry Curvature ◽  
Hall Effects ◽  
Fundamental Understanding ◽  
Spin Hall Effects ◽  
Theoretical Results

AbstractThe physics of the anomalous and spin Hall effects is one of the most intriguing aspects of condensed matter physics. An important finding from a large collection of experimental and theoretical results is the universal scaling of the anomalous or spin Hall conductivity with the electric conductivity. This scaling has been successfully described by the intrinsic Berry curvature and extrinsic scattering mechanisms for metallic systems, revealing the topological nature of these effects. In contrast, the underlying physics in the opposite limit, the disordered insulating regime, is still unclear. In particular, it remains a major challenge, both experimentally and theoretically, to explore the spin Hall effect in the insulating regime. Here, we report the observation of the crossover between the metallic and insulating regimes of the spin Hall effect. The result demonstrates a direct correspondence between the spin and anomalous Hall effects, which will advance the fundamental understanding of spin transport.

scholarly journals Observation of the crossover between metallic and insulating regimes of the spin Hall effect

2021 ◽  
Author(s):  
Hiroyuki Moriya ◽  
Akira Musha ◽  
Satoshi Haku ◽  
Kazuya Ando
Keyword(s):  
Hall Effect ◽  
Condensed Matter ◽  
Spin Hall Effect ◽  
Large Collection ◽  
Essential Information ◽  
Berry Curvature ◽  
Hall Effects ◽  
Fundamental Understanding ◽  
Spin Hall Effects ◽  
Theoretical Results

Abstract The physics of the anomalous and spin Hall effects is one of the most intriguing aspects of condensed matter physics. An important finding from a large collection of experimental and theoretical results is the universal scaling of the anomalous or spin Hall conductivity with the electric conductivity. This scaling has been successfully described by the intrinsic Berry curvature and extrinsic scattering mechanisms for metallic systems, revealing the topological nature of these effects. In contrast, the underlying physics in the opposite limit, the disordered insulating regime, is still unclear. In particular, it remains a major challenge to explore the spin Hall effect in the insulating regime. Here, we report the observation of the crossover between the metallic and insulating regimes of the spin Hall effect. The result demonstrates an important correspondence between the spin and anomalous Hall effects, which provides essential information for the fundamental understanding of spin transport.

scholarly journals Enhancement of perpendicular magnetic anisotropy and transmission of spin-Hall-effect-induced spin currents by a Hf spacer layer in W/Hf/CoFeB/MgO layer structures

2014 ◽  
Vol 104 (8) ◽  
pp. 082407 ◽  
Author(s):  
Chi-Feng Pai ◽  
Minh-Hai Nguyen ◽  
Carina Belvin ◽  
Luis Henrique Vilela-Leão ◽  
D. C. Ralph ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Hall Effect ◽  
Perpendicular Magnetic Anisotropy ◽  
Spin Hall Effect ◽  
Spin Currents ◽  
Layer Structures ◽  
Spacer Layer

scholarly journals Orbital torque in magnetic bilayers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dongjoon Lee ◽  
Dongwook Go ◽  
Hyeon-Jong Park ◽  
Wonmin Jeong ◽  
Hye-Won Ko ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Hall Effect ◽  
Spin Current ◽  
Spin Hall Effect ◽  
Spin Orbit ◽  
Magnetic Torque ◽  
Device Applications ◽  
Metal Bilayers ◽  
Experiment Analysis ◽  
Theory And Experiment

AbstractThe orbital Hall effect describes the generation of the orbital current flowing in a perpendicular direction to an external electric field, analogous to the spin Hall effect. As the orbital current carries the angular momentum as the spin current does, injection of the orbital current into a ferromagnet can result in torque on the magnetization, which provides a way to detect the orbital Hall effect. With this motivation, we examine the current-induced spin-orbit torques in various ferromagnet/heavy metal bilayers by theory and experiment. Analysis of the magnetic torque reveals the presence of the contribution from the orbital Hall effect in the heavy metal, which competes with the contribution from the spin Hall effect. In particular, we find that the net torque in Ni/Ta bilayers is opposite in sign to the spin Hall theory prediction but instead consistent with the orbital Hall theory, which unambiguously confirms the orbital torque generated by the orbital Hall effect. Our finding opens a possibility of utilizing the orbital current for spintronic device applications, and it will invigorate researches on spin-orbit-coupled phenomena based on orbital engineering.

scholarly journals A New Approach to Transport Coefficients in the Quantum Spin Hall Effect

2020 ◽  
Author(s):  
Giovanna Marcelli ◽  
Gianluca Panati ◽  
Stefan Teufel
Keyword(s):  
Hall Effect ◽  
Constant Electric Field ◽  
Transport Coefficients ◽  
Spin Current ◽  
Spin Operator ◽  
Quantum Spin ◽  
Spin Hall Effect ◽  
Current Operator ◽  
Quantum Spin Hall Effect ◽  
Quantum Spin Hall

AbstractWe investigate some foundational issues in the quantum theory of spin transport, in the general case when the unperturbed Hamiltonian operator $$H_0$$ H 0 does not commute with the spin operator in view of Rashba interactions, as in the typical models for the quantum spin Hall effect. A gapped periodic one-particle Hamiltonian $$H_0$$ H 0 is perturbed by adding a constant electric field of intensity $$\varepsilon \ll 1$$ ε ≪ 1 in the j-th direction, and the linear response in terms of a S-current in the i-th direction is computed, where S is a generalized spin operator. We derive a general formula for the spin conductivity that covers both the choice of the conventional and of the proper spin current operator. We investigate the independence of the spin conductivity from the choice of the fundamental cell (unit cell consistency), and we isolate a subclass of discrete periodic models where the conventional and the proper S-conductivity agree, thus showing that the controversy about the choice of the spin current operator is immaterial as far as models in this class are concerned. As a consequence of the general theory, we obtain that whenever the spin is (almost) conserved, the spin conductivity is (approximately) equal to the spin-Chern number. The method relies on the characterization of a non-equilibrium almost-stationary state (NEASS), which well approximates the physical state of the system (in the sense of space-adiabatic perturbation theory) and allows moreover to compute the response of the adiabatic S-current as the trace per unit volume of the S-current operator times the NEASS. This technique can be applied in a general framework, which includes both discrete and continuum models.

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