Coexistence of superconductivity and weak anti-localization at KTaO3 (111) interfaces

TL;DR

This study reports the coexistence of two-dimensional superconductivity and weak anti-localization at TiOx/KTaO3(111) interfaces, revealing complex quantum phenomena and potential topological states.

Contribution

It demonstrates the simultaneous presence of superconductivity and weak anti-localization at a single interface, a novel observation in this material system.

Findings

Superconductivity persists with residual resistance below transition temperature.

Weak anti-localization signatures are observed alongside superconductivity.

Superconducting interfaces exhibit significantly larger weak anti-localization corrections.

Abstract

The intersection of two-dimensional superconductivity and topologically nontrivial states hosts a wide range of quantum phenomena, including Majorana fermions. Coexistence of topologically nontrivial states and superconductivity in a single material, however, remains elusive. Here, we report on the observation of two-dimensional superconductivity and weak anti-localization at the TiOx/KTaO3(111) interfaces. A remnant, saturating resistance persists below the transition temperature as superconducting puddles fail to reach phase coherence. Signatures of weak anti-localization are observed below the superconducting transition, suggesting the coexistence of superconductivity and weak anti-localization. The superconducting interfaces show roughly one order of magnitude larger weak anti-localization correction, compared to non-superconducting interfaces, alluding to a relatively large coherence length in these interfaces.