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arXiv · 0803.4490

Controlling the spontaneous emission of a superconducting transmon qubit

A. A. Houck·J. A. Schreier·B. R. Johnson·J. M. Chow·Jens Koch·J. M. Gambetta·D. I. Schuster·L. Frunzio·M. H. Devoret·S. M. Girvin·R. J. Schoelkopf
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Abstract

We present a detailed characterization of coherence in seven transmon qubits in a circuit QED architecture. We find that spontaneous emission rates are strongly influenced by far off-resonant modes of the cavity and can be understood within a semiclassical circuit model. A careful analysis of the spontaneous qubit decay into a microwave transmission-line cavity can accurately predict the qubit lifetimes over two orders of magnitude in time and more than an octave in frequency. Coherence times $T_1$ and $T_2^*$ of more than a microsecond are reproducibly demonstrated.

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A. A. Houck, J. A. Schreier, B. R. Johnson, J. M. Chow, Jens Koch, J. M. Gambetta, D. I. Schuster, L. Frunzio, M. H. Devoret, S. M. Girvin, R. J. Schoelkopf. 2008-03-31. Controlling the spontaneous emission of a superconducting transmon qubit. https://doi.org/10.1103/physrevlett.101.080502

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