Spin polarization in quantum wires: Influence of Dresselhaus spin-orbit interaction and cross-section effects

Abstract

We examine the effects of the full Dresselhaus spin-orbit coupling on laterally confined quantum wire states. An analysis of the relative contributions due to linear, quadratic, and cubic Dresselhaus spin-orbit terms on the energy levels, spin splitting, and spin polarization has been carried out. The effects of wire cross-sectional geometry shapes on the electronic structure are explored. In particular we compared the results of semicylindrical and cylindrical confinements and have found important differences between the spin degeneracy of the ground-state level and the spin-polarization dependence on sign inversion of the free linear momentum quantum number along the wire axis. Different from other symmetries, in both cases here considered, the stronger spin-splitting effects come from the quadratic Dresselhaus term. We report ideal conditions for realization of spin-field filter devices based on symmetry properties of the spin splitting of the ground state in semicylindrical quantum wires.

Intrinsic spin-orbit effect in substrate-graphene Corbino devices

“…Although the intrinsic spin orbit does not lift the degeneracy of electron spin per se in a monolayer graphene, the presence of a substrate in the system produces an energy contribution from substrate–graphene interaction that will compete with those coming from SOI for each electron spin character, giving rise to resultant energy whose difference features breaking of the degeneracy of states with different electron spin. Here, we can note a similarity with the Dresselhaus SOI (). Therefore, in the absence of substrate the electron‐spin degeneracy is restored, even if is finite in Eq.…”

Spin-orbit coupling and electric-dipole spin resonance in a nanowire double quantum dot

“…Experimentally, electron occupancy of quantum dots in a nanowire can be effectively controlled by regulating the local gate electrodes [32][33][34][35] . Recently, nanowires with narrow bandgap, large SOC, and large g-factor have been of particular interest because they present intriguing opportunities for studying fast electrical control of spins [19][20][21][25][26][27] , possible manipulation of entangled spins 30,31 , and hybrid structures made of a superconductor and a large-SOC nanowire are a promising system to search for Majorana fermions 28,29 .…”

“…Over the past decade semiconductor nanowire devices have attracted wide attention because of their one-dimensionality, convenience of growth, and a variety of interesting physical properties [19][20][21][22][23][24][25][26][27][28][29] . Experimentally, electron occupancy of quantum dots in a nanowire can be effectively controlled by regulating the local gate electrodes [32][33][34][35] .…”

Majorana Zero Modes in Cylindrical Semiconductor Quantum Wire

“…1) separates into a free-particle contribution along the wire and a radial confinement contribution. 63,64 The Hamiltonian is…”