Anomalous flux periodicity in proximitised quantum spin Hall constrictions
| Autor: | Vigliotti, Lucia, Calzona, Alessio, Trauzettel, Björn, Sassetti, Maura, Ziani, Niccolò Traverso |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | New J. Phys. 2022, 24, 053017 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1367-2630/ac643b |
| Popis: | We theoretically analyse a long constriction between the helical edge states of a two-dimensional topological insulator. The constriction is laterally tunnel-coupled to two superconductors and a magnetic field is applied perpendicularly to the plane of the two-dimensional topological insulator. The Josephson current is calculated analytically up to second order in the tunnel coupling both in the absence and in the presence of a bias (DC and AC Josephson currents). We show that in both cases the current acquires an anomalous $4\pi$-periodicity with respect to the magnetic flux that is absent if the two edges are not tunnel-coupled to each other. The result, that provides at the same time a characterisation of the device and a possible experimental signature of the coupling between the edges, is stable against temperature. The processes responsible for the anomalous $4\pi$-periodicity are the ones where, within the constriction, one of the two electrons forming a Cooper pair tunnels between the two edges. Comment: 29 pages, 9 figures |
| Databáze: | arXiv |
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