Fluxon cotunneling in coupled Josephson junctions: Perturbation theory
Fluxon cotunneling in coupled Josephson junctions: Perturbation theory
We investigate the effects of fluxon cotunneling and quantum Coulomb drag in a system of two small Josephson junctions coupled by means of mutual capacitance $C_m$. Depending on the value of $C_m$ we identify three different regimes of strong, intermediate and weak coupling. Focusing our attention on the last two regimes we develop a perturbation theory in the interaction and explicitly derive fluxon cotunneling amplitudes at sufficiently small mutual capacitance values. We demonstrate that the Coulomb drag effect survives at any non-zero $C_m$ and evaluate the non-local voltage response that is in general determined by a trade off between two different cotunneling processes. Our predictions can be straightforwardly generalized to bilinear Josephson chains and directly verified in future experiments.
Andrew G. Semenov、Alex Latyshev、Andrei D. Zaikin
物理学
Andrew G. Semenov,Alex Latyshev,Andrei D. Zaikin.Fluxon cotunneling in coupled Josephson junctions: Perturbation theory[EB/OL].(2025-05-10)[2025-07-09].https://arxiv.org/abs/2505.06720.点此复制
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