paper

Time-dependent driving and topological protection in the fractional Josephson effect

arXiv:2306.09440 · doi:10.1103/PhysRevB.109.245423

Abstract

The control of any type of quantum hardware invariably necessitates time-dependent driving. If the basis depends on the control parameter, the presence of a time-dependent control field yields an extra term in the Schrödinger equation that is often neglected. Here, we examine the effect of this term in a flux-controlled Majorana junction. We show that a time-varying flux gives rise to an electromotive force which is amplified when truncating to the junction's low-energy degrees of freedom. As a result, it compromises the robustness of the ground-state degeneracy present in the absence of the drive. The resulting flattening of the energy spectrum can be measured by a strong suppression of the dc supercurrent.

6 pages, 3 figures; supplementary material (5 pages, 1 figure) at the end of main text

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