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Spectral response of Josephson junctions with low-energy quasiparticles

by Anna Keselman, Chaitanya Murthy, Bernard van Heck, Bela Bauer

Submission summary

As Contributors: Anna Keselman · Chaitanya Murthy
Preprint link: scipost_201906_00002v1
Date submitted: 2019-06-19
Submitted by: Keselman, Anna
Submitted to: SciPost Physics
Domain(s): Theor. & Comp.
Subject area: Condensed Matter Physics - Theory

Abstract

We study nanowire-based Josephson junctions shunted by a capacitor and take into account the presence of low-energy quasiparticle excitations. These are treated by extending conventional models used to describe superconducting qubits to include the coherent coupling between fermionic quasiparticles, in particular the Majorana zero modes that emerge in topological superconductors, and the plasma mode of the junction. Using accurate, unbiased matrix-product state techniques, we compute the energy spectrum and response function of the system across the topological phase transition. Furthermore, we develop a perturbative approach, valid in the harmonic limit with small charging energy, illustrating how the presence of low-energy quasiparticles affects the spectrum and response of the junction. Our results are of direct interest to on-going experimental investigations of nanowire-based superconducting qubits.

Current status:
Editor-in-charge assigned

Submission & Refereeing History

Submission scipost_201906_00002v1 on 19 June 2019

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