Theory of an infinitely anisotropic phase of a two-dimensional superconductor

TL;DR

This paper introduces a model of a two-dimensional anisotropic superconductor with direction-dependent non-linear electrical behavior, potentially explaining experimental observations of anisotropic critical temperatures in interfacial superconductivity.

Contribution

It presents a simple theoretical model capturing anisotropic non-linear I-V characteristics and relates it to recent experimental findings on interfacial superconductivity.

Findings

Power-law non-linear I-V behavior with different exponents in two directions

Potential explanation for directional dependence of critical temperature

Relevance to experimental observations in EuO/KTaO3(110) interfaces

Abstract

We propose a simple model of a two-dimensional ``locally smectic superconductor'' that exhibits power-law non-linear I-V characteristics with different powers for current applied in two orthogonal directions. We discuss the potential relevance of this model to recent experimental findings on interfacial superconductivity in EuO/KTaO$_3$(110) (Nat. Phys. 20, 957 (2024)), where the apparent critical temperature ($T_c$) has been shown experimentally to depend on the current direction.