Controlling the spontaneous emission of a superconducting transmon qubit.
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 T_{2};{*} of more than a microsecond are reproducibly demonstrated.
Houck
A A
AA
Departments of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520, USA.
Schreier
J A
JA
Johnson
B R
BR
Chow
J M
JM
Koch
Jens
J
Gambetta
J M
JM
Schuster
D I
DI
Frunzio
L
L
Devoret
M H
MH
Girvin
S M
SM
Schoelkopf
R J
RJ