Odd momentum pairing and superconductivity in vertical graphene heterostructures

TL;DR

This paper explores how vertical graphene heterostructures can host an unconventional odd momentum pairing superconducting state mediated by modified electron interactions, with potential high transition temperatures.

Contribution

It demonstrates the theoretical possibility of odd momentum pairing superconductivity in vertical graphene heterostructures with detailed analysis of transition temperature dependencies.

Findings

Superconductivity with opposite sign gaps in different valleys is possible.

Odd momentum pairing state can exist at high carrier densities.

Transition temperature depends on device parameters.

Abstract

Vertical graphene heterostructures made up of graphene layers separated by BN spacers allow for novel ways of tuning the interactions between electrons. We study the possibility of electron pairing mediated by modified repulsive interactions. Long range intravalley and short range intervalley interactions give rise to different anisotropic phases. We show that a superconducting state with gaps of opposite signs in different valleys, an odd momentum pairing state, can exist above carrier densities of $5-10 \times 10^{13} {\rm cm}^{-2}$. The dependence of the transition temperature on the different parameters of the devices is studied in detail.