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

doi:10.1103/PhysRevLett.101.080502

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

DOI 10.1103/PhysRevLett.101.080502 · Physical Review Letters

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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 2 orders of magnitude in time and more than an octave in frequency. Coherence times T1 and T2* of more than a microsecond are reproducibly demonstrated.

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Formula	Reported Tc (K)	Pressure (GPa)	Type
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