Gate-tunable anomalous transverse voltage at the superconducting LaAlO3/SrTiO3 interface

Abstract

An anomalous transverse voltage near the superconducting transition is observed at the LaAlO3/SrTiO3 heterointerface. In contrast to the normal Hall effects, the observed anomalous transverse voltage persists even at zero magnetic field and is an even function of the magnetic field. It also responds anisotropically to out-of-plane and in-plane magnetic fields. Due to the two-dimensional nature of this superconducting electron system, this anomalous transverse signal is highly tunable via electrostatic gating. Strikingly, the temperature dependence of this transverse voltage exhibits a gate-tunable sign reversal behavior and can even undergo multiple sign reversals. Thorough analyses indicate that the anomalous transverse signal can be largely attributed to the guided vortex motion in the two-dimensional superconducting system. Our findings not only reveal important aspects of vortex dynamics at the strongly correlated oxide interface but also may promote the development of electrically tunable vortex dynamics.