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 Berezinskii-Kosterlitz-Thouless topological effects. We show this limitation can be overcome using a superlattice of alternating electron-doped 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 Tc can be at room temperature. As a quantitative illustration, we show Tc can reach 270 K for a superfluid in a realistic superlattice of transition metal dichalcogenide monolayers.
About the speaker
Prof David Neilson jointly proposed the first practical exciton superfluid system in atomically-thin materials, (key to FLEET’s Research theme 2), which has recently been observed. He works with FLEET researchers to identify additional promising candidates for dissipationless electronic transport in atomically-thin materials and on optimising their performance.