Observation of the quantum Hall effect in cleaved InAs surfaces

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 NsNs is determined from the Hall coefficient at 1.5K. The coverage dependence of NsNs 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 μμ is about 0.3T-1 and does not show a clear dependence on the coverage over 0.03ML. In the high-magnetic field regime of B>1/μB>1/μ, Shubnikov–de Hass oscillations were observed. A beating pattern due to the strong spin–orbit interaction appears for high NsNs. For lower NsNs of 1.04×1012cm-2, an apparent quantum Hall plateau for ν=4ν=4 and vanishing of the longitudinal resistivity were observed around B=10.8T.