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arXiv · 0803.3102

Kinetics of non-equilibrium quasiparticle tunneling in superconducting charge qubits

M. D. Shaw·R. Lutchyn·P. Delsing·P. M. Echternach
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Abstract

We directly observe low-temperature non-equilibrium quasiparticle tunneling in a pair of charge qubits based on the single Cooper-pair box. We measure even- and odd-state dwell time distributions as a function of temperature, and interpret these results using a kinetic theory. While the even-state lifetime is exponentially distributed, the odd-state distribution is more heavily weighted to short times, implying that odd-to-even tunnel events are not described by a homogenous Poisson process. The mean odd-state dwell time increases sharply at low temperature, which is consistent with quasiparticles tunneling out of the island before reaching thermal equilibrium.

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M. D. Shaw, R. Lutchyn, P. Delsing, P. M. Echternach. 2008-04-05. Kinetics of non-equilibrium quasiparticle tunneling in superconducting charge qubits. https://doi.org/10.1103/physrevb.78.024503

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