Energy relaxation time between macroscopic quantum levels in a superconducting persistent-current qubit.
We measured the intrawell energy relaxation time tau(d) approximately 24 micros between macroscopic quantum levels in the double well potential of a Nb persistent-current qubit. Interwell population transitions were generated by irradiating the qubit with microwaves. Zero population in the initial well was then observed due to a multilevel decay process in which the initial population relaxed to lower energy levels during the driven transitions. The decoherence time, estimated from tau(d) within the spin-boson model, is about 20 micros for this configuration with a Nb superconducting qubit.
Yu
Yang
Y
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nakada
D
D
Lee
Janice C
JC
Singh
Bhuwan
B
Crankshaw
D S
DS
Orlando
T P
TP
Berggren
Karl K
KK
Oliver
William D
WD