Superfluid state of magnetoexcitons in double layer graphene structures

TL;DR

This paper investigates the conditions under which superfluid magnetoexcitons can form in double layer graphene structures under strong magnetic fields, highlighting the role of filling factor imbalance and potential for high-temperature superfluidity.

Contribution

It introduces the theoretical analysis of superfluid magnetoexcitons in graphene double layers, including excitation spectra and transition temperature dependence, emphasizing advantages over traditional heterostructures.

Findings

Superfluid magnetoexcitons require filling factor imbalance.

Transition temperature depends on interlayer distance.

Graphene double layers offer advantages over GaAs heterostructures.

Abstract

The possibility of realization of a superfluid state of bound electron-hole pairs (magnetoexcitons) with spatially separated components in a graphene double layer structure (two graphene layers separated by a dielectric layer) subjected by a strong perpendicular to the layers magnetic field is analyzed. We show that the superfluid state of magnetoexcitons may emerge only under certain imbalance of filling factors of the layers. The imbalance can be created by an electrostatic field (external gate voltage). The spectrum of elementary excitations is found and the dependence of the Berezinskii-Kosterlitz-Thouless transition temperature on the interlayer distance is obtained. The advantages of use graphene double layer systems instead of double quantum well GaAs heterostructures are discussed.