scholarly journals Generation of DC, AC, and Second-Harmonic Spin Currents by Electromagnetic Fields in an Inversion-Asymmetric Antiferromagnet

2019 ◽  
Vol 4 (4) ◽  
pp. 92
Author(s):  
Tatsuhiko N. Ikeda

Manipulating spin currents in magnetic insulators is a key technology in spintronics. We theoretically study a simple inversion-asymmetric model of quantum antiferromagnets, where both the exchange interaction and the magnetic field are staggered. We calculate spin currents generated by external electric and magnetic fields by using a quantum master equation. We show that an ac electric field with amplitude E 0 leads, through exchange-interaction modulation, to the dc and second-order harmonic spin currents proportional to E 0 2 . We also show that dc and ac staggered magnetic fields B 0 generate the dc and ac spin currents proportional to B 0 , respectively. We elucidate the mechanism by an exactly solvable model, and thereby propose the ways of spin current manipulation by electromagnetic fields.

Author(s):  
E. Saitoh ◽  
K. Ando

This chapter introduces the concept of exchange spin current, which derives from rewriting the exchange interaction in magnets and formulating a spin-wave spin current. States of matter can be classified into several types in terms of magnetic properties. In paramagnetic and diamagnetic states, matter has no magnetic order and exhibits zero magnetization in the absence of external magnetic fields. In ferromagnetic states, the permanent magnetic moments of atoms or ions align parallel to a certain direction, and the matter exhibits finite magnetization even in the absence of external magnetic fields. In ferrimagnets, the moments align antiparallel but the cancellation is not perfect and net magnetization appears. This interaction that aligns spins is called the exchange interaction.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
X. R. Wang

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.


2014 ◽  
Vol 80 (3) ◽  
pp. 865-892 ◽  
Author(s):  
Paul D Ledger ◽  
William R B Lionheart

Abstract We rigorously derive the leading-order terms in asymptotic expansions for the scattered electric and magnetic fields in the presence of a small object at distances that are large compared with its size. Our expansions hold for fixed wavenumber when the scatterer is a (lossy) homogeneous dielectric object with constant material parameters or a perfect conductor. We also derive the corresponding leading-order terms in expansions for the fields for a low-frequency problem when the scatterer is a non-lossy homogeneous dielectric object with constant material parameters or a perfect conductor. In each case, we express our results in terms of polarization tensors.


Author(s):  
Abraham O. Rodríguez-De la Fuente ◽  
J. Antonio Heredia-Rojas ◽  
Pilar Carranza-Rosales ◽  
Omar Heredia-Rodríguez ◽  
Gerardo Lozano-Garza ◽  
...  

JOUTICA ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 255
Author(s):  
Kemal Farouq Mauladi ◽  
Nurul Fuad

Telecommunications technology is developing very rapidly, ranging from users or engineers. The development of smartphone smartphones is also increasingly in demand, so that the use of electricity needs is also increasing. The need for electricity usage has resulted in more standing voltage in some settlements. The establishment of sutet will have a negative impact on public health. In addition, the influence of electrical energy on humans occurs because the electrical energy generated by electricity generation or electricity that is channeled gives rise to electromagnetic fields. The higher the voltage required by an equipment, the greater the electric field that is distributed. Besides that, it can also find ways to reduce the negative impact of the electric and magnetic fields produced by SUTET which impacts the process of the occurrence of electric and magnetic fields on SUTET. From the problems above, the author intends to determine the effect or correlation between the impact of SUTET on cellphone network transmissions or channels. This research can later determine the negative impact caused by SUTET for the surrounding community, and the impact of SUTET radiation on cellular networks.


2008 ◽  
Vol 74 (1) ◽  
pp. 111-118
Author(s):  
FEN-CE CHEN

AbstractThe acceleration of ions by multiple laser pulses and their spontaneously generated electric and magnetic fields is investigated by using an analytical model for the latter. The relativistic equations of motion of test charged particles are solved numerically. It is found that the self-generated axial electric field plays an important role in the acceleration, and the energy of heavy test ions can reach several gigaelectronvolts.


2020 ◽  
Vol 34 (13) ◽  
pp. 2050129
Author(s):  
Erhan Albayrak

The A, B and C atoms with spin-1/2, spin-3/2 and spin-5/2 are joined together sequentially on the Bethe lattice in the form of ABCABC[Formula: see text] to simulate a molecule as a triple mixed-spin system. The spins are assumed to be interacting with only their nearest-neighbors via bilinear exchange interaction parameter in addition to crystal and external magnetic fields. The order-parameters are obtained in terms of exact recursion relations, then from the study of their thermal variations, the phase diagrams are calculated on the possible planes of our system. It is found that the model gives only second-order phase transitions in addition to the compensation temperatures.


2011 ◽  
Vol 106 (16) ◽  
Author(s):  
Robin Steinigeweg ◽  
Stephan Langer ◽  
Fabian Heidrich-Meisner ◽  
Ian P. McCulloch ◽  
Wolfram Brenig

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