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arXiv · 1406.6301

Theory of microwave spectroscopy of Andreev bound states with a Josephson junction

L. Bretheau·Ç. Girit·M. Houzet·H. Pothier·D. Esteve·C. Urbina
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Abstract

We present a microscopic theory for the current through a tunnel Josephson junction coupled to a non-linear environment, which consists of an Andreev two-level system coupled to a harmonic oscillator. It models a recent experiment [Bretheau, Girit, Pothier, Esteve, and Urbina, Nature (London) 499, 312 (2013)] on photon spectroscopy of Andreev bound states in a superconducting atomic-size contact. We find the eigenenergies and eigenstates of the environment and derive the current through the junction due to inelastic Cooper pair tunneling. The current-voltage characteristic reveals the transitions between the Andreev bound states, the excitation of the harmonic mode that hybridizes with the Andreev bound states, as well as multi-photon processes. The calculated spectra are in fair agreement with the experimental data.

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L. Bretheau, Ç. Girit, M. Houzet, H. Pothier, D. Esteve, C. Urbina. 2014-06-24. Theory of microwave spectroscopy of Andreev bound states with a Josephson junction. https://doi.org/10.1103/physrevb.90.134506

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