Determination of Rashba-coupling strength for surface two-dimensional electron gas in InAs nanowires

Abstract

A key concept in the field of semiconductor spintronics is an electric field control of spins via the spin-orbit coupling (SOC) and the SOC strength governs efficiency of this control. We propose a new approach that allows the experimental determination of the Rashba SOC strength for ballistic InAs nanowires. The energy spectrum and ballistic transport of carriers through the nanowire with surface two-dimensional electron gas (2DEG) in a homogeneous magnetic field are studied. A general formula for the linear-response one-dimensional ballistic thermopower is derived in the case of complex subband structure. The ballistic conductance and the thermopower are shown to reveal specific features due to strong SOC that allows us to propose a method for the SOC strength determination.

Electronic states and persistent currents in nanowire quantum ring

“…Using one-particle Hamiltonian of NW with TEG [13,14], that takes into account both Rashba and k-linear Dresselhaus SOC, after dimension quantization along NW axis, we find the following effective-mass Hamiltonian for carriers in NWQR…”

Effect of spin–orbit coupling on spectral and transport properties of tubular electron gas in InAs nanowires

“…If the magnetic field B is included in consideration then the Zeemann splitting H Z has to be taken into account and we have to include the influence of magnetic field on orbital motion by substitution p → p − (e/c)A with p and A being the electron momentum and vector potential, respectively. In this case the Hamiltonian of the system with RSOC only H 0 = H k + H R + H Z is given by [8]…”

“…Thus, the spectral problem for reduced total Hamiltonian having only first term from H D can be solved analytically (as in Ref. [8]). This leads to renormalization of SO-gaps width (in units of E 0 )…”

“…The effect of Rashba SOC (RSOC) on the energy spectrum and ballistic transport in InAs NW was recently studied [8]. However, the influence of the lack of inversion center in semiconductor material constituting the nanostructure [9] was not considered.…”

Enhancement of Rashba interaction in GaAs/AlGaAs quantum wells due to the incorporation of bismuth

“…6 The narrowgap semiconductors InAs and InSb exhibit the strongest conduction spin-orbit coupling due to large atomic masses and low effective electron mass (m * ) and have been much reported for this reason. [7][8][9][10] The largest observed ∆E SIA have been reported for asymmetric InSb/InAlSb quantum well (QW) structures where the typical conduction band spin splitting is of the order of 3 meV. 11 This has led to the demonstration of spin dependent electron transport in these structures at temperatures up to approximately 20 K and spin coherence lengths of up to 2µm.…”