Electric field effect on superconductivity at complex oxide interfaces

TL;DR

This paper investigates how applying an electric field at complex oxide interfaces, specifically LaAlO$_{3}$/SrTiO$_{3}$, can enhance superconductivity by breaking inversion symmetry and modifying carrier density, leading to potential control of superconducting properties.

Contribution

It introduces a mechanism where electric fields influence superconductivity at oxide interfaces by coupling to superfluid density and altering carrier density, supported by microscopic and capacitance measurements.

Findings

Electric field enhances interfacial superconductivity.

Breaking inversion symmetry affects superfluid density.

Electric field modifies carrier density and transition temperature.

Abstract

We examine the enhancement of the interfacial superconductivity between LaAlO$_{3}$ and SrTiO$_{3}$ by an effective electric field. Through the breaking of inversion symmetry at the interface, we show that a term coupling the superfluid density and an electric field can augment the superconductivity transition temperature. Microscopically, we show that an electric field can also produce changes in the carrier density by relating the measured capacitance to the density of states. Through the electron-phonon induced interaction in bulk SrTiO$_{3}$, we estimate the transition temperature.