Weak localization and spin splitting in inversion layers on $p$-type InAs

We report on the magnetoconductivity of quasi-two-dimensional electron systems in inversion layers on $p$-type InAs single crystals. In low magnetic fields pronounced features of weak localization and antilocalization are observed. They are almost perfectly described by the theory of Iordanskii, Lyanda-Geller, and Pikus. This allows us to determine the spin splitting and the Rashba parameter of the ground electric subband as a function of the electron density.

Figure 1

(a) Experimental magnetoconductance for a gate voltage of $V_g=15\mathrm{V}$ at $T=2.65\mathrm{K}$ (solid line) as well as a calculated Drude parabola (dashed line). (b) Schematic of the sample geometry. The radius of the inner electrode is $300\mu \mathrm{m}$, the channel length $100\mu \mathrm{m}$, and the radius of the outer electrode $700\mu \mathrm{m}$. (c) Electron mobility versus gate voltage.

Figure 2

Experimental magnetoconductances recorded at 2.65 K for various gate voltages (solid lines). The classical Drude conductance is subtracted. Theoretical conductances (dashed lines) are calculated from the theory of Iordanskii, Lyanda-Geller, and Pikus (Refs. 17, 18).

Figure 3

(a) Spin-splitting energy at the Fermi level. Theoretical data are taken from Lamari (Ref. 22) and Winkler (Ref. 23). (b) Rashba parameter. Dashed and solid lines are calculated for the spin-split subbands at the Fermi level (Ref. 22). (c) Occupation of the spin-split subbands. Open and closed symbols are data for spin-down and spin-up states of the two different samples indicated by circles and squares. Theoretical curves are taken from Lamari (Ref. 7).