Liu, Ming-Hao and Wu, Jhih-Sheng and Chen, Son-Hsien and Chang, Ching-Ray
Spin and charge transport in U-shaped one-dimensional channels with spin-orbit couplings.
Physical Review B (PRB) 84 (8), 085307.
A general form of the Hamiltonian for electrons confined to a curved one-dimensional (1D) channel with spin-orbit coupling (SOC) linear in momentum is rederived and is applied to a U-shaped channel. Discretizing the derived continuous 1D Hamiltonian to a tight-binding version, the Landauer–Keldysh formalism (LKF) for nonequilibrium transport can be applied. Spin transport through the U-channel based on the LKF is compared with previous quantum mechanical approaches. The role of a curvature-induced geometric potential which was previously neglected in the literature of the ring issue is also revisited. Transport regimes between nonadiabatic, corresponding to weak SOC or sharp turn, and adiabatic, corresponding to strong SOC or smooth turn, is discussed. Based on the LKF, interesting charge and spin transport properties are further revealed. For the charge transport, the interplay between the Rashba and the linear Dresselhaus (001) SOCs leads to an additional modulation to the local charge density in the half-ring part of the U-channel, which is shown to originate from the angle-dependent spin-orbit potential. For the spin transport, theoretically predicted eigenstates of the Rashba rings, Dresselhaus rings, and the persistent spin-helix state are numerically tested by the present quantum transport calculation.
|Date:||22 August 2011|
|Institutions:|| Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Klaus Richter|
|Research groups and research centres:||Not selected|
|Subjects:||500 Science > 530 Physics|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Partially|
Dr. Ming-Hao Liu
|Deposited On:||22 Jun 2011 06:22|
|Last Modified:||30 Aug 2011 13:30|