Spin currents, spin-transfer torque, and spin-Hall effects in relativistic quantum mechanics

2007 ◽  
Vol 76 (1) ◽  
Author(s):  
A. Vernes ◽  
B. L. Györffy ◽  
P. Weinberger
Keyword(s):  
Quantum Mechanics ◽  
Relativistic Quantum ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Relativistic Quantum Mechanics ◽  
Spin Currents ◽  
Hall Effects ◽  
Spin Hall Effects

scholarly journals Subterahertz spin pumping from an insulating antiferromagnet

Science ◽  
2020 ◽  
Vol 368 (6487) ◽  
pp. 160-165 ◽  
Author(s):  
Priyanka Vaidya ◽  
Sophie A. Morley ◽  
Johan van Tol ◽  
Yan Liu ◽  
Ran Cheng ◽  
...  
Keyword(s):  
Magnetic Moments ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Pure Spin ◽  
Spin Pumping ◽  
Hall Effects ◽  
Terahertz Frequencies ◽  
Platinum Layer ◽  
And Control ◽  
Spin Hall Effects

Spin-transfer torque and spin Hall effects combined with their reciprocal phenomena, spin pumping and inverse spin Hall effects (ISHEs), enable the reading and control of magnetic moments in spintronics. The direct observation of these effects remains elusive in antiferromagnetic-based devices. We report subterahertz spin pumping at the interface of the uniaxial insulating antiferromagnet manganese difluoride and platinum. The measured ISHE voltage arising from spin-charge conversion in the platinum layer depends on the chirality of the dynamical modes of the antiferromagnet, which is selectively excited and modulated by the handedness of the circularly polarized subterahertz irradiation. Our results open the door to the controlled generation of coherent, pure spin currents at terahertz frequencies.

GAUGE INVARIANCE IN NON-RELATIVISTIC MANY-BODY THEORY

1992 ◽  
Vol 06 (11n12) ◽  
pp. 2201-2208 ◽  
Author(s):  
J. FRÖHLICH ◽  
U.M. STUDER
Keyword(s):  
Quantum Mechanics ◽  
Gauge Invariance ◽  
Relativistic Quantum ◽  
Relativistic Quantum Mechanics ◽  
Two Dimensional ◽  
Spin Liquids ◽  
Many Body ◽  
Many Body Theory ◽  
Hall Effects ◽  
Body Theory

We review some recent results on the physics of two-dimensional, incompressible electron and spin liquids. These results follow from Ward identities reflecting the U(1) em × SU(2) spin -gauge invariance of non-relativistic quantum mechanics. They describe a variety of generalized quantized Hall effects.

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.

Stochastic microcausality in relativistic quantum mechanics

1984 ◽  
Vol 14 (9) ◽  
pp. 883-906 ◽  
Author(s):  
D. P. Greenwood ◽  
E. Prugovečki
Keyword(s):  
Quantum Mechanics ◽  
Relativistic Quantum ◽  
Relativistic Quantum Mechanics

Relativistic Multiple Scattering Theory

1991 ◽  
Vol 253 ◽  
Author(s):  
B. L. Gyorffy
Keyword(s):  
Quantum Mechanics ◽  
Degrees Of Freedom ◽  
Relativistic Quantum ◽  
Schr6dinger Equation ◽  
Relativistic Effects ◽  
Relativistic Quantum Mechanics ◽  
Absolute Minimum ◽  
Crystalline Anisotropy ◽  
Symmetry Properties ◽  
Finite Set

The symmetry properties of the Dirac equation, which describes electrons in relativistic quantum mechanics, is rather different from that of the corresponding Schr6dinger equation. Consequently, even when the velocity of light, c, is much larger than the velocity of an electron Vk, with wave vector, k, relativistic effects may be important. For instance, while the exchange interaction is isotropic in non-relativistic quantum mechanics the coupling between spin and orbital degrees of freedom in relativistic quantum mechanics implies that the band structure of a spin polarized metal depends on the orientation of its magnetization with respect to the crystal axis. As a consequence there is a finite set of degenerate directions for which the total energy of the electrons is an absolute minimum. Evidently, the above effect is the principle mechanism of the magneto crystalline anisotropy [1]. The following session will focus on this and other qualitatively new relativistic effects, such as dichroism at x-ray frequencies [2] or Fano effects in photo-emission from non-polarized solids [3].

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