Current-driven reduction of topological protection in multichannel superconductors
Abstract
We investigate the robustness of topological phases in a Kitaev ladder composed of two coupled superconducting chains under the perturbing influence of a finite charge current. By introducing an effective Hamiltonian depending on the quasiparticle momentum induced by the current, we show that the two-mode topological phase, present in the isolated ladder, is fragile against a finite current flux. To characterize this behavior, we combine bulk topological invariants with real-space diagnostics, including the edge--edge quantum conditional mutual information Iee, which provides an entanglement-based signature of topological order. We further distinguish the gapped class-D sectors from a current-induced gapless superconducting regime, which emerges when the upper BdG branch crosses zero at generic momenta and the standard gapped topological invariant is no longer applicable. Our results provide an effective framework to describe how current injection and measurement processes can affect topological protection in superconducting nanostructures.
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BibTeX
@misc{maiellaro2026currentdriven,
title = {{Current-driven reduction of topological protection in multichannel superconductors}},
author = {Alfonso Maiellaro},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2605.22460},
eprint = {2605.22460},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.22460},
}
RIS
TY - UNPB
TI - Current-driven reduction of topological protection in multichannel superconductors
AU - Alfonso Maiellaro
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2605.22460
UR - https://arxiv.org/abs/2605.22460
AB - We investigate the robustness of topological phases in a Kitaev ladder composed of two coupled superconducting chains under the perturbing influence of a finite charge current. By introducing an effective Hamiltonian depending on the quasiparticle momentum induced by the current, we show that the two-mode topological phase, present in the isolated ladder, is fragile against a finite current flux. To characterize this behavior, we combine bulk topological invariants with real-space diagnostics, including the edge--edge quantum conditional mutual information I_ee, which provides an entanglement-based signature of topological order. We further distinguish the gapped class-D sectors from a current-induced gapless superconducting regime, which emerges when the upper BdG branch crosses zero at generic momenta and the standard gapped topological invariant is no longer applicable. Our results provide an effective framework to describe how current injection and measurement processes can affect topological protection in superconducting nanostructures.
ER -