Weak (anti)localization in tubular semiconductor nanowires with spin-orbit coupling

Abstract

We compute analytically the weak (anti)localization correction to the Drude conductivity for electrons in tubular semiconductor systems of zinc-blende type. We include linear Rashba and Dresselhaus spin-orbit coupling (SOC) and compare wires of standard growth directions 100 , 111 , and 110 . The motion on the quasi-twodimensional surface is considered diffusive in both directions: transversal as well as along the cylinder axis. It is shown that Dresselhaus and Rashba SOC similarly affect the spin relaxation rates. For the 110 growth direction, the long-lived spin states are of helical nature. We detect a crossover from weak localization to weak antilocalization depending on spin-orbit coupling strength as well as dephasing and scattering rate. The theory is fitted to experimental data of an undoped 111 InAs nanowire device which exhibits a top-gate-controlled crossover from positive to negative magnetoconductivity. Thereby, we extract transport parameters where we quantify the distinct types of SOC individually.

Magnetoconductance correction in zinc-blende semiconductor nanowires with spin-orbit coupling

“…Similar to the 2D and quasi-1D cases [14,32], the effect of Rashba SOC becomes manifest in an effective vector potential A s = Q so A s where A s =h/(2e)(S z ,0, − S x ) and therefore couples to the Cooperon momentum. In contrast, the Dresselhaus SOC leads to a term ∝λ D = 8 2 /35, where = k 2 F γ D /α R , which does not couple to the wave vector Q and is diagonal in the triplet sector.…”

“…where α R = γ R E. For convenience and in analogy to previous publications [14,33,34,42], we define the Cooperon HamiltonianĤ c = (hD eĈ ) −1 . An additional Taylor expansion of the integrand in Eq.…”

“…Below, we follow the approach in Refs. [14,[32][33][34]42] to compute the quantum correction to the conductivity.…”

“…In disordered systems, the conductivity is either enhanced or reduced due to quantum interference, which is denoted as weak antilocalization (WAL) or weak localization (WL), respectively. By fitting the experimental data with an appropriate theoretical model, it is possible to extract SOC strengths as well as dephasing, scattering, and, most prominently, spin relaxation rates [9][10][11][12][13][14][15][16][17][18]. Notably, a crossover from WAL to WL can even indicate spin-preserving symmetries [19][20][21].…”

“…The WAL/WL effect in the diffusive regime was analyzed by Kettemann [32] and Wenk [33,34] for planar quantum wires with a zinc-blende lattice. In our preceding article [14], we developed a model for diffusive zinc-blende nanowires where the transport is governed by surface states, which occurs in materials with Fermi level surface pinning [12,25,30,35,36] or core/shell nanowires [26].…”