Two-Dimensional Superconductivity at the Titanium Sesquioxide Heterointerface

TL;DR

This paper reports the discovery of two-dimensional superconductivity at the Ti₂O₃/GaN heterointerface with a transition temperature of 3.8 K, revealing new quantum phenomena and potential for high-$T_c$ heterostructure superconductors.

Contribution

First experimental observation of 2D superconductivity at a Ti₂O₃/GaN heterointerface, expanding understanding of emergent phenomena at heterostructures.

Findings

Superconductivity with $T_c$ up to 3.8 K observed at the heterointerface.

Detection of a quantum metallic-like state near the superconducting transition.

First report of superconductivity at the Ti₂O₃/GaN heterointerface.

Abstract

The study of exotic superconductivity in two dimensions has been a central theme in solid state and materials research communities. Experimentally exploring and identifying new fascinating interface superconductors with a high transition temperature ($T_c$) is challenging. Here, we report an experimental observation of intriguing two-dimensional superconductivity with a $T_c$ up to 3.8 K at the interface between Mott insulator Ti$_2$O$_3$ and polar semiconductor GaN. At the verge of superconductivity, we also observe a striking quantum metallic-like state, demonstrating that it is a precursor to the two-dimensional superconductivity as the temperature is decreased. Our work is the first time finding this intriguing superconducting state at the heterointerface, which not only brings a new broad of perspective on the emergent quantum phenomena at the heterointerfaces but also sheds new light on exploiting the novel heterointerface superconductivity with high-$T_c$ via heterostructure engineering.