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arXiv · 1512.04244

Dynamical polaron ansatz: a theoretical tool for the ultra-strong coupling regime of circuit QED

Guillermo Díaz-Camacho·Alejandro Bermudez·Juan José García-Ripoll
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Abstract

In this work we develop a semi-analytical variational ansatz to study the properties of few photon excitations interacting with a collection of quantum emitters in regimes that go beyond the rotating wave approximation. This method can be used to approximate both the static and dynamical properties of a superconducting qubit in an open transmission line, including the spontaneous emission spectrum and the resonances in scattering experiments. The approximations are quantitatively accurate for rather strong couplings, as shown by a direct comparison to Matrix-Product-State numerical methods, and provide also a good qualitative description for stronger couplings well beyond the Markovian regime.

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Guillermo Díaz-Camacho, Alejandro Bermudez, Juan José García-Ripoll. 2015-12-14. Dynamical polaron ansatz: a theoretical tool for the ultra-strong coupling regime of circuit QED. https://doi.org/10.1103/physreva.93.043843

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