Energy Relaxation Time between Macroscopic Quantum Levels in a Superconducting Persistent-Current Qubit
Abstract
We measured the intrawell energy relaxation time τd≃24 μs 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 τd within the spin-boson model, is about 20 μs for this configuration with a Nb superconducting qubit.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2004
- DOI:
- arXiv:
- arXiv:cond-mat/0311289
- Bibcode:
- 2004PhRvL..92k7904Y
- Keywords:
-
- 03.67.Pp;
- 03.65.Yz;
- 85.25.Cp;
- 85.25.Dq;
- Quantum error correction and other methods for protection against decoherence;
- Decoherence;
- open systems;
- quantum statistical methods;
- Josephson devices;
- Superconducting quantum interference devices;
- Condensed Matter - Superconductivity
- E-Print:
- 18 pages, 5 figures