Cleaved InSb Surfaces Research Articles

Adsorbate-induced quantum Hall system probed by scanning tunneling spectroscopy combined with transport measurements

An adsorbate-induced quantum Hall system at the cleaved InSb surfaces is investigated in magnetic fields up to 14 T using low-temperature scanning tunneling microscopy and spectroscopy combined with transport measurements. We show that an enhanced Zeeman splitting in the Shubnikov-de Haas oscillations is explained by an exchange enhancement of spin splitting and potential disorder, both of which are obtained from the spatially averaged density of states (DOS). Moreover, the Altshuler–Aronov correlation gap is observed in the spatially averaged DOS at 0 T.

Quantum Hall effect at cleaved InSb surfaces and low-temperature annealing effect

The authors have performed low-temperature in-plane magnetotransport measurements on two-dimensional electron systems induced by deposition of Ag at in situ cleaved surfaces of p-type InSb. The quantum Hall effect was observed even at low magnetic fields around 2T. The surface electron density and the electron mobility exhibit strong dependence on the Ag coverage and the annealing temperature in the range of 15–40K. The annealing effect suggests that the surface morphology strongly affects the properties of the two-dimensional electron systems.