Spin splitting modulated by uniaxial stress in InAs nanowires

Abstract

We theoretically study the electronic structure, spin splitting, effective mass,and spin orientation of InAs nanowires with cylindrical symmetry in thepresence of an external electric field and uniaxial stress. Using an eight-bandk·p theoretical model, we deduce a formula for the spin splitting in the system, indicating thatthe spin splitting under uniaxial stress is a nonlinear function of the momentum and theelectric field. The spin splitting can be described by a linear Rashba model when thewavevector and the electric field are sufficiently small. Our numeric results show that theuniaxial stress can modulate the spin splitting. With the increase of wavevector, theuniaxial tensile stress first restrains and then amplifies the spin splitting of the lowestelectron state compared to the no strain case. The reverse is true under a compression.Moreover, strong spin splitting can be induced by compression when the top ofthe valence band is close to the bottom of the conductance band, and the spinorientations of the electron stay almost unchanged before the overlap of the two bands.