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arXiv · 1507.08881

$\mathbb{Z}_4$ Parafermions \& the $8π$-periodic Josephson effect in interacting Rashba nanowires

Chris J. Pedder·Tobias Meng·Rakesh P. Tiwari·Thomas L. Schmidt
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Abstract

We demonstrate the appearance of zero-energy bound states satisfying the $\mathbb{Z}_4$ parafermionic algebra in interacting quantum wires with Rashba spin-orbit coupling and proximity-induced superconductivity. The fourfold degeneracy of these states is protected by time-reversal symmetry and fermion-parity conservation, and leads to an $8 π$ periodicity of the Josephson current due to the tunneling of fractionalized excitations with charge $e/2$. Even in the presence of perturbations, we propose that this periodicity will remain visible in driven, current-biased Shapiro step measurements on current state-of-the-art Rashba wires.

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Chris J. Pedder, Tobias Meng, Rakesh P. Tiwari, Thomas L. Schmidt. 2016-02-08. $\mathbb{Z}_4$ Parafermions \& the $8π$-periodic Josephson effect in interacting Rashba nanowires. https://arxiv.org/abs/1507.08881

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