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arXiv · 1508.01799

Signatures of topological phase transitions in Josephson current-phase discontinuities

Pasquale Marra·Roberta Citro·Alessandro Braggio
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Abstract

Topological superconductors differ from topologically trivial ones for the presence of topologically protected zero-energy modes. To date, experimental evidence of topological superconductivity in nanostructures has been mainly obtained by measuring the zero-bias conductance peak via tunneling spectroscopy. Here, we propose an alternative and complementary experimental recipe to detect topological phase transitions in these systems. We show in fact that, for a finite-sized system with broken time-reversal symmetry, discontinuities in the Josephson current-phase relation correspond to the presence of zero-energy modes and to a change in the fermion parity of the groundstate. Such discontinuities can be experimentally revealed by a characteristic temperature dependence of the current, and can be related to a finite anomalous current at zero phase in systems with broken phase-inversion symmetry.

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Pasquale Marra, Roberta Citro, Alessandro Braggio. 2016-04-25. Signatures of topological phase transitions in Josephson current-phase discontinuities. https://doi.org/10.1103/physrevb.93.220507

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