Spin and Orbital Angular Momentum Hall Effects in Two Dimensional Electron Systems
Date Issued
2005
Date
2005
Author(s)
Huang, Chih-Meng
DOI
en-US
Abstract
The spin Hall effect means that an electric field can induce a transverse spin current even in the absence of magnetic field. By generating the dissipationless spin current, the spin Hall effect has important applications in
spintronics. The effective definition of spin current in a spin-orbit system is introduced while the conventional spin current is intuitively thought of as the spin flux. In the linear response limit, we rederive the spin Hall conductivity in a two dimension electron system(2DES) with Rashba spin-orbit system.Similarly, we also define an effective orbital angular momentum(OAM) cur-rent in a spin-orbit system by the same way and discover it existed non-zero OAM Hall current in a pure Rashba system.
Besides Rashba system, we also consider Dresselhuas spin-orbit coupling into the 2DES. The Dresselhaus term stemmed form the bulk inversion sym-metry and the term is comparable with the Rashba term(e.g. GaAs). We predict that the OAM Hall conductivity is relative to the ratio of the two couplings and independent on the carrier density. Due to the non-conservation of total angular momentum in the presence of Dresselhaus term, the spin Hall current doesn’t cancel with the OAM Hall current. It causes a finite magnetization Hall current(or angular momentum current ). When the two couplings are comparable, the OAM Hall conductivity is divergent.
spintronics. The effective definition of spin current in a spin-orbit system is introduced while the conventional spin current is intuitively thought of as the spin flux. In the linear response limit, we rederive the spin Hall conductivity in a two dimension electron system(2DES) with Rashba spin-orbit system.Similarly, we also define an effective orbital angular momentum(OAM) cur-rent in a spin-orbit system by the same way and discover it existed non-zero OAM Hall current in a pure Rashba system.
Besides Rashba system, we also consider Dresselhuas spin-orbit coupling into the 2DES. The Dresselhaus term stemmed form the bulk inversion sym-metry and the term is comparable with the Rashba term(e.g. GaAs). We predict that the OAM Hall conductivity is relative to the ratio of the two couplings and independent on the carrier density. Due to the non-conservation of total angular momentum in the presence of Dresselhaus term, the spin Hall current doesn’t cancel with the OAM Hall current. It causes a finite magnetization Hall current(or angular momentum current ). When the two couplings are comparable, the OAM Hall conductivity is divergent.
Subjects
自旋霍爾效應
軌道角動量霍爾效應
spin Hall effect
orbital angular momentum Hall effect
Type
thesis
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