Anisotropic intrinsic spin Hall effect in quantum wires

Abstract

We use numerical simulations to investigate the spin Hall effect in quantum wires in the presence of both Rashba and Dresselhaus spin-orbit coupling. We find that the intrinsic spin Hall effect is highly anisotropic with respect to the orientation of the wire, and that the nature of this anisotropy depends strongly on the electron density and the relative strengths of the Rashba and Dresselhaus spin-orbit couplings. In particular, at low densities, when only one subband of the quantum wire is occupied, the spin Hall effect is strongest for electron momentum along the [N110] axis, which is the opposite of what is expected for the purely 2D case. In addition, when more than one subband is occupied, the strength and anisotropy of the spin Hall effect can vary greatly over relatively small changes in electron density, which makes it difficult to predict which wire orientation will maximize the strength of the spin Hall effect. These results help to illuminate the role of quantum confinement in spin-orbit-coupled systems, and can serve as a guide for future experimental work on the use of quantum wires for spin-Hall-based spintronic applications.

Open quantum dots: Physics of the non‐Hermitian Hamiltonian

“…The starting point for our approach is a general Hamiltonian which is discretized upon a rectilinear grid [50]. While it is easy to incorporate the magnetic field, this approach has been extended to treat dissipation in nanowire transistors [51] and to incorporate spin and the Rashba and Dresselhaus spin-orbit terms [52]. On the grid, a tridiagonal matrix represents the Hamiltonian for the individual isolated slices I, where a slice is the column of the grid normal to the direction of current flow.…”