Josephson effect as signature of electron-hole superfluidity in bilayers of van der Waals heterostructures

Abstract

We investigate a Josephson junction in an electron-hole superfluid in a double layer TMD heterostructure. 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, for the first time in a semiconductor system, an experimental way to determine the position of this boundary.

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Cited by in corpus (4)

• Excitonic insulators and superfluidity in 2D bilayers without external fields
• Edge modes in chiral electron double layers
• Exciton Superfluidity in 2D Heterostructures from First Principles: The importance of material specific screening
• Chiral Josephson effect in double layers: the role of particle-hole duality