Superfluid stiffness of a KTaO3-based two-dimensional electron gas

S. Mallik, G. C. Ménard, L. Benfatto, M. Bibes, G. Saïz, H. Witt, J. Lesueur & N. Bergeal

After almost twenty years of intense work on the celebrated LaAlO3 /SrTiO3 system, the recent discovery of a superconducting two-dimensional electron gas (2-DEG) in (111)-oriented KTaO3 -based heterostructures injects new momentum to the field of oxides interface. However, while both interfaces share common properties, experiments also suggest important differences between the two systems. Here, we report gate tunable superconductivity in 2-DEGs generated at the surface of a (111)-oriented KTaO3 crystal by the simple sputtering of a thin Al layer. We extract the superfluid stiffness of the 2-DEGs and show that its temperature dependence is consistent with a node-less superconducting order parameter having a gap value larger than expected within a simple BCS weak-coupling limit model. The superconducting transition follows the Berezinskii-Kosterlitz-Thouless scenario, which was not reported on SrTiO3 -based interfaces. Our finding offers innovative perspectives for fundamental science but also for device applications in a variety of fields such as spin-orbitronics and topological electronics.

Nature Communications 2022

Haut de page

À lire aussi...

Effect of disorder on superconductivity and Rashba spin-orbit coupling in LaAlO3/SrTiO3 interfaces

by G. Singh, A. Jouan, S. Hurand, C. Feuillet-Palma, P. Kumar, A. Dogra, R. Budhani, J. Lesueur and N. Bergeal A rather unique feature of the (...) 

> Lire la suite...

Josephson-like dynamics of the superconducting LaAlO3/SrTiO3 interface

by S. Hurand, A. Jouan, E. Lesne, G. Singh, C. Feuillet-Palma, M. Bibes, A. Barthélémy, J. Lesueur, and N. Bergeal In this article, we show that (...) 

> Lire la suite...