Three-dimensional electron-hole superfluidity in a superlattice close to room temperature

TL;DR

This paper proposes a superlattice structure of alternating electron- and hole-doped monolayers to achieve high-temperature electron-hole superfluidity, potentially reaching room temperature, overcoming previous 2D fluctuation limitations.

Contribution

It introduces a 3D superlattice design that enables high-temperature superfluidity, surpassing the constraints of 2D systems and Kosterlitz-Thouless effects.

Findings

Superfluid transition temperature can reach 270 K in realistic superlattices.

3D superlattice structure overcomes 2D fluctuation limitations.

Transition temperature is not limited by topological constraints.

Abstract

Although there is strong theoretical and experimental evidence for electron-hole superfluidity in separated sheets of electrons and holes at low $T$, extending superfluidity to high $T$ is limited by strong 2D fluctuations and Kosterlitz-Thouless effects. We show this limitation can be overcome using a superlattice of alternating electron- and hole-doped semiconductor monolayers. The superfluid transition in a 3D superlattice is not topological, and for strong electron-hole pair coupling, the transition temperature $T_c$ can be at room temperature. As a quantitative illustration, we show $T_c$ can reach $270$ K for a superfluid in a realistic superlattice of transition metal dichalcogenide monolayers.