Modulation of superconducting transition temperature in LaAlO$_{3}$/SrTiO$_{3}$ by SrTiO$_{3}$ structural domains

TL;DR

This study investigates how the structural domains in SrTiO$_{3}$ influence the spatial variation of the superconducting transition temperature in LaAlO$_{3}$/SrTiO$_{3}$ heterostructures, revealing a domain-related modulation of superconductivity.

Contribution

It demonstrates the direct correlation between SrTiO$_{3}$ structural domains and inhomogeneous superconducting transition temperatures in LAO/STO.

Findings

Superconducting transition temperature varies spatially in LAO/STO.

The pattern of variation correlates with SrTiO$_{3}$ structural domains.

Superconductivity is modulated by the underlying domain structure.

Abstract

The tetragonal domain structure in SrTiO$_{3}$ (STO) is known to modulate the normal-state carrier density in LaAlO$_{3}$/SrTiO$_{3}$ (LAO/STO) heterostructures, among other electronic properties, but the effect of STO domains on the superconductivity in LAO/STO has not been fully explored. Using a scanning SQUID susceptometer microscope to map the superconducting response as a function of temperature in LAO/STO, we find that the superconducting transition temperature is spatially inhomogeneous and modulated in a pattern that is characteristic of structural domains in the STO.