Observation of the quantum Hall effect in cleaved InAs surfaces

Abstract

We have performed the in-plane magnetotransport measurements on the two-dimensional electron gas at the cleaved p-InAs (1 1 0) surface by deposition of Ag. The surface electron density N s is determined from the Hall coefficient at 1.5 K . The coverage dependence of N s is well explained by the assumption that each adsorbed Ag atom denotes one electron into InAs until the surface Fermi level reaches the adsorbate-induced donor level. The electron mobility μ is about 0.3 T - 1 and does not show a clear dependence on the coverage over 0.03 ML . In the high-magnetic field regime of B > 1 / μ , Shubnikov–de Hass oscillations were observed. A beating pattern due to the strong spin–orbit interaction appears for high N s . For lower N s of 1.04 × 10 12 cm - 2 , an apparent quantum Hall plateau for ν = 4 and vanishing of the longitudinal resistivity were observed around B = 10.8 T .