Electronic-grade epitaxial (111) KTaO3 heterostructures

TL;DR

This paper reports the development of superconducting heterostructures using high-quality epitaxial (111) KTaO3 thin films, demonstrating enhanced electron mobility and superconducting properties due to cleaner interfaces, advancing the study of quantum phenomena in these materials.

Contribution

It introduces a novel hybrid epitaxial growth method for high-quality KTaO3 thin films, enabling better interfaces for quantum property exploration.

Findings

Higher electron mobility in heterostructures compared to bulk KTaO3.

Increased superconducting transition temperature and critical current.

Cleaner interfaces lead to improved quantum properties.

Abstract

KTaO3 has recently attracted attention as a model system to study the interplay of quantum paraelectricity, spin-orbit coupling, and superconductivity. However, the high and low vapor pressures of potassium and tantalum present processing challenges to creating interfaces clean enough to reveal the intrinsic quantum properties. Here, we report superconducting heterostructures based on electronic-grade epitaxial (111) KTaO3 thin films. Electrical and structural characterizations reveal that two-dimensional electron gas at the heterointerface between amorphous LaAlO3 and KTaO3 thin film exhibits significantly higher electron mobility, superconducting transition temperature and critical current density than those in bulk single crystal KTaO3-based heterostructures owing to cleaner interface in KTaO3 thin films. Our hybrid approach may enable epitaxial growth of other alkali metal-based oxides that lie beyond the capabilities of conventional methods.