Spin‐orbit coupling in gated AlGaN/GaN 2‐dimensional electron gases

Abstract

Weak antilocalization was studied in an AlxGa1−xN/GaN two-dimensional electron gas as a function of temperature for various gate voltages. By fitting the weak antilocalization measurements by a theoretical model we found that the spin-orbit scattering length does not vary upon changing the carrier concentration or the temperature. The occurrence of spin-orbit coupling was attributed to the crystal inversion asymmetry. The presence of beating patterns observed in the Shubnikov-de Haas oscillations were not assigned to the presence of spin-orbit coupling but rather to structural inhomogeneities in the Al xGa1−xN/GaN crystal.

Spin dynamics in semiconductors

“…Indeed, experiments revealed that the spin-orbit coupling is dominated by the Rashba-type spin-orbit coupling, where no effect that signals spin-orbit coupling of the form of (k x σ x − k y σ y ) was observed [247,[256][257][258][259][260]. The measured Rashba parameter lies in the range of 0.6 to 8 × 10 −12 eV m various conditions [251][252][253][254][261][262][263][264][265][266][267][268].…”

“…The non-monotonic temperature dependence of the spin relaxation time originates from the non-monotonic temperature dependence of the electron-electron and electron-hole scattering times, as noted from Eqs. (268) and (269). 84 The peak is then located in the crossover regime.…”

Spin dynamics in semiconductors

“…Indeed, experiments revealed that the spin-orbit coupling is dominated by the Rashba-type spin-orbit coupling, where no effect that signals spin-orbit coupling of the form of (k x σ x − k y σ y ) was observed [247,[256][257][258][259][260]. The measured Rashba parameter lies in the range of 0.6 to 8×10 −12 eV•m for various conditions [251][252][253][254][261][262][263][264][265][266][267][268].…”