Excitonic Josephson effect in double-layer graphene junctions

Abstract

We show that double-layer graphene (DLG), where an external potential induces an charge-imbalance between $n$- and $p$-type layers, is a promising candidate to realize an exciton condensate in equilibrium. To prove this phenomenon experimentally, we suggest to couple two DLG systems, separated by a thin insulating barrier, and measure the excitonic Josephson effect. For this purpose we calculate the ac and dc Josephson currents induced by tunneling excitons and show that the former only occurs when the gate potentials of the DLG systems differ, irrespective of the phase relationship of their excitonic order parameters. A dc Josephson current develops if a finite order-parameter phase difference exists between two coupled DLG systems with identical gate potentials.

5 pages, 4 figures, revised version

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Cited by in corpus (3)

• Josephson effect as signature of electron-hole superfluidity in bilayers of van der Waals heterostructures
• Excitonic Tunneling in the AB-bilayer Graphene Josephson Junctions
• Role of the compensating current in the weak Josphson coupling regime: An extended study on excitonic Josephson junctions