Determining Rashba spin-orbit coupling strength in InSb nanowire quantum dots: Influence of temperature and nuclear environment⋆

Abstract

We identify theoretically the possibility to determine the Rashba spin-orbit coupling strength in InSb nanowire quantum dots by measuring the magnetic susceptibility of the two-electron system in a double quantum dot. To realistically describe such a system, we study the role of finite temperature and the interaction of the double quantum dot spins with the nuclear environment. Magnetic susceptibility, a quantity dependent on the relative angle between the magnetic and the spin-orbit field, reaches a maximal value when the spin-orbit and magnetic field are parallel/antiparallel to each other. We show that the dependence of the peak with respect to the magnetic field orientation, being a controllable quantity, can be used to extract the value of the Rashba parameter in materials with strong spin-orbit coupling. Since the strength of the Rashba parameter is independent of the confinement along the nanowire axis, the determined value can be used in configurations with different gating potential profiles and the number of electrons trapped inside the quantum dot system.