Freiburg 2019 – scientific programme

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FM: Fall Meeting

FM 39: Quantum Computation: Hardware Platforms II

FM 39.3: Talk

Tuesday, September 24, 2019, 14:45–15:00, 3044

Non-equilibrium quasiparticles in superconducting circuits: photons vs. phonons — •Gianluigi Catelani¹ and Denis Basko² — ¹JARA Institute for Quantum Information, Forschungszentrum Jülich, Germany — ²CNRS, Grenoble, France

We study the effect of non-equilibrium quasiparticles on the operation of a superconducting device (a qubit or a resonator), including heating of the quasiparticles by the device operation. Focusing on the competition between heating via low-frequency photon absorption and cooling via photon and phonon emission, we obtain a remarkably simple non-thermal stationary solution of the kinetic equation for the quasiparticle distribution function. We estimate the influence of quasiparticles on relaxation and excitation rates for transmon qubits, and relate our findings to recent experiments.