Orientational tuning of the 2D-superconductivity in LaAlO3/SrTiO3 interfaces

TL;DR

This study investigates how the crystallographic orientation of LaAlO3/SrTiO3 interfaces affects 2D superconductivity, revealing orientation-dependent differences in superconducting properties and electronic structure.

Contribution

It provides the first detailed analysis of 2D superconductivity at (110)-oriented LaAlO3/SrTiO3 interfaces, highlighting the impact of orientation on superconducting extension and electronic behavior.

Findings

Superconductivity extends over 24-30 nm at (110) interfaces.

No violation of the Pauli paramagnetic limit observed.

Orientation influences the electronic structure and superconducting properties.

Abstract

The discovery of a two-dimensional (2D) electron gas at the (110)-oriented LaAlO3/SrTiO3 in- terface provided us with the opportunity to probe the effect of crystallographic orientation and the ensuing electronic reconstructions on interface properties beyond the conventional (001)-orientation. At temperatures below 200 mK, we have measured 2D superconductivity with a spatial extension significantly larger (d approx. 24 - 30 nm) than previously reported for (001)-oriented LaAlO3/SrTiO3 interfaces (d approx. 10 nm). The more extended superconductivity brings about the absence of violation of the Pauli paramagnetic limit for the upper critical fields, signaling the distinctive nature of the electronic structure of the (110)-oriented interface with respect to their (001)-counterparts