Toward High Temperature Quasi-two-dimensional Superconductivity

TL;DR

This paper proposes all-oxide heterostructures with ferroelectric components to achieve switchable, high-temperature quasi-two-dimensional superconductivity, potentially enabling advanced electronic devices.

Contribution

It introduces a novel design of heterostructures incorporating ferroelectric materials to realize high-temperature, switchable 2D superconductivity based on first-principles calculations.

Findings

Prediction of high-temperature quasi-2D superconductivity in ferroelectric heterostructures.

Proposal that ferroelectric polarization reversal can switch superconductivity on and off.

Simpler fabrication process for such heterostructures compared to existing methods.

Abstract

The demonstration of a quasi-two-dimensional electron gas (2DEG) and superconducting properties in LaAlO$_3$/SrTiO$_3$ heterostructures has stimulated intense research activity in recent ten years. The 2DEG has unique properties that are promising for applications in all-oxide electronic devices. The superconductivity in such heterostructures has been observed below 300 mK. For superconductivity applications it is desirable to have more wide temperature of the existence range and the ability to control superconductivity properties by external stimulus. Based on first-principles calculations and theoretical consideration we show that all-oxide heterostructures incorporating ferroelectric constituent, such as BaTiO$_3$/La$_2$CuO$_4$, allow creating 2DEG. We predict a possibility of a high temperature guasi-two-dimensional superconductivity state. This state could be switchable between superconducting and conducting states by ferroelectric polarization reversal. We also discuss that such structures must be more simple for preparation. The proposed concept of ferroelectrically controlled interface superconductivity offers the possibility to design novel electronic devices.