General conditions for proximity-induced odd-frequency superconductivity in two-dimensional electronic systems

TL;DR

This paper establishes broad conditions under which odd-frequency superconductivity can occur in 2D systems coupled to superconductors, and demonstrates it in a heterostructure involving transition metal dichalcogenides and Rashba spin-orbit coupling.

Contribution

It provides the first general theoretical framework for odd-frequency pairing in 2D proximity systems, applicable to various materials and heterostructures.

Findings

Odd-frequency pairing occurs under specific proximity conditions.

Heterostructure with transition metal dichalcogenide and Rashba coupling exhibits odd-frequency pairing.

Odd-frequency amplitude is proportional to the product of spin-orbit couplings.

Abstract

We obtain the general conditions for the emergence of odd-frequency superconducting pairing in a two-dimensional (2D) electronic system proximity-coupled to a superconductor, making minimal assumptions about both the 2D system and the superconductor. Using our general results we show that a simple heterostructure formed by a monolayer of a group VI transition metal dichalcogenide, such as molybdenum disulfide, and an s-wave superconductor with Rashba spin-orbit coupling will exhibit odd-frequency superconducting pairing. Furthermore, we show that in such a heterostructure the odd-frequency pairing amplitude will be proportional to the product of the Rashba spin-orbit coupling in the substrate and the spin-orbit coupling in the dichalcogenide layer.