INFLUENCE OF SPIN-ORBIT INTERACTION ON THE MAGNETOTRANSPORT OF A PERIODICALLY MODULATED TWO-DIMENSIONAL ELECTRON GAS

摘要

Transport properties of a two-dimensional electron gas (2DEG) are studied in the presence of a normal magnetic field B, of a weak one-dimensional (1D) periodic potential modulation V(x) = V_0cos(KX), and of the Rashba spin-orbit interaction (SOI) of strength α. For V(x) = 0 the SOI mixes the up and down spin states of neighboring Landau levels into two, unequally spaced energy branches. For V(x)≠0 these levels broaden into bands and their bandwidths oscillate with B. The n-th level bandwidth of each series vanishes at different values of B. Relative to the 1D-modulated 2DEG without SOI and one flat-band condition, there are two flat-band conditions that depend on α and the transport coefficients can change considerably. For weak α the Weiss oscillations show beating patterns while for strong α the Shubnikov-de Haas ones are split in two.