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arXiv · 1612.05418

Topological transconductance quantization in a four-terminal Josephson junction

Erik Eriksson·Roman-Pascal Riwar·Manuel Houzet·Julia S. Meyer·Yuli V. Nazarov
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Abstract

Recently we predicted that the Andreev bound state spectrum of 4-terminal Josephson junctions may possess topologically protected zero-energy Weyl singularities, which manifest themselves in a quantized transconductance in units of $4e^2/h$ when two of the terminals are voltage biased [R.-P. Riwar et al., Nature Commun. 7, 11167 (2016)]. Here, using the Landauer-B\"uttiker scattering theory, we compute numerically the currents flowing through such a structure in order to assess the conditions for observing this effect. We show that the voltage below which the transconductance becomes quantized is determined by the interplay of non-adiabatic transitions between Andreev bound states and inelastic relaxation processes. We demonstrate that the topological quantization of the transconductance can be observed at voltages of the order of $10^{-2} \Delta/e$, $\Delta$ being the superconducting gap in the leads.

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Erik Eriksson, Roman-Pascal Riwar, Manuel Houzet, Julia S. Meyer, Yuli V. Nazarov. 2016-12-16. Topological transconductance quantization in a four-terminal Josephson junction. https://doi.org/10.1103/physrevb.95.075417

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