Multifractal spectra of extended states with gate tunable Rashba spin-orbit interaction in two-dimensional electron systems Academic Article in Scopus uri icon

abstract

  • © 2019 Author(s).In a two dimensional electron gas with disorder, subjected to a strong magnetic field and in the presence of homogeneous Rashba spin-orbit coupling (SOC), the extended states that lie close to the center of each spin resolved Landau level (LL) have multifractal nature. In this work, multifractal analysis has been performed to extended states that lie close to the center of the spin unresolved lowest LL and the spin resolved first LL. Using both, a gaussian white noise potential and a series of short range scatterers as the source of disorder, the numerical results are found to agree within the statistical deviation. We have found that the multifractal exponents of extended states close to the center of the spin unresolved lowest LL and the spin down oriented first LL, are independent of the SOC parameter ¿d. However, the multifractal exponents of extended states close to the center of the spin up oriented first LL depend on ¿d. For these states, the inverse participation number, which characterizes the extent of localization of a given state, is observed to be an increasing function of ¿d, indicating that these states are less extended for stronger SOCs. This is in contrast to the effects of SOC on weak localization physics, where it tends to increase the conductivity and reduce localization.

publication date

  • September 1, 2019