Observation of Superconductivity on the Rashba-Type Surface Reconstruction (Tl, Pb)/Si(111) by in situ Electrical Transport Measurements

Abstract

A surface reconstruction consisting of one monolayer of Tl and one-third monolayer of Pb on a Si(111) was found to exhibit a large Rashba-type spin splitting in the metallic surface-state bands together with two-dimensional superconductivity. Temperature dependent angle-resolved photoelectron spectroscopy revealed a strong electron-phonon interaction in one of the bands. In situ four-point-probe resistivity measurements with and without magnetic field demonstrated that the (Tl, Pb)/Si(111) system transited into the superconducting state at 2.3 K. The (Tl, Pb)/Si(111) is a prototypical system for prospective studies of intriguing properties of the space-inversion-symmetry-broken superconductor.