corner
corner

Phys. Rev. B 80, 212503 (2009) [4 pages]

Noise-induced quantum coherence and persistent Rabi oscillations in a Josephson flux qubit

Download: PDF (357 kB) Buy this article Export: BibTeX or EndNote (RIS)

A. N. Omelyanchouk1, S. Savel’ev2,3, A. M. Zagoskin2,3, E. Il’ichev4, and Franco Nori3,5
1B.Verkin Institute for Low Temperature Physics and Engineering, 61103 Kharkov, Ukraine
2Department of Physics, Loughborough University, Leicestershire LE11 3TU, United Kingdom
3Digital Materials Laboratory, Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198, Japan
4Institute of Photonic Technology (IPHT-Jena), P.O. Box 100239, D-07702 Jena, Germany
5Center for Theoretical Physics, Physics Department, Center for the Study of Complex Systems, The University of Michigan, Ann Arbor, Michigan 48109-1040, USA

Received 14 September 2009; published 30 December 2009

We predict theoretically the enhancement of quantum coherence in a superconducting flux qubit by a classical external noise. First, the off-diagonal components of the qubit density matrix are increased. Second, in the presence of both ac drive and noise, the resulting Rabi oscillations survive “in perpetuity,” i.e., for times greatly exceeding the Rabi decay time in a noiseless system. The coherence-enhancing effects of the classical noise can be considered as a manifestation of quantum stochastic resonance and are relevant to experimental techniques, such as Rabi spectroscopy.

© 2009 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.80.212503
DOI:
10.1103/PhysRevB.80.212503
PACS:
74.50.+r, 05.40.-a, 03.67.Lx, 05.30.-d