Excitonic Josephson effect in double-layer graphene junctions

Zenker, B.; Fehske, H.; Beck, Hans

doi:10.1103/PhysRevB.92.081111

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Journal article

Excitonic Josephson effect in double-layer graphene junctions

Zenker, B. Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, Germany
Fehske, H. Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, Germany
Beck, Hans Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, Switzerland

17.08.2015

Published in:

Physical Review B. - 2015, vol. 92, no. 8, p. 081111

English We show that double-layer graphene (DLG), where an external potential induces a 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 coupling two DLG systems, separated by a thin insulating barrier, and measuring 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.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

Language