- Letter
Josephson effect as a signature of electron-hole superfluidity in bilayers of van der Waals heterostructures
Phys. Rev. B 106, L220503 – Published 19 December, 2022
DOI: https://doi.org/10.1103/PhysRevB.106.L220503
Abstract
We investigate a Josephson junction in an electron-hole superfluid in a double-layer transition metal dichalcogenide heterostructure. The observation of a critical tunneling current is a clear signature of superfluidity. In addition, we find the BCS-BEC crossover physics in the narrow barrier region controls the critical current across the entire system. The corresponding critical velocity, which is measurable in this system, has a maximum when the excitations pass from bosonic to fermionic. Remarkably, this occurs for the density at the boundary of the BEC to BCS-BEC crossover regime determined from the condensate fraction. This provides, in a semiconductor system, an experimental way to determine the position of this boundary.
