Noise and decoherence in quantum two-level systems
摘要
Motivated by recent experiments with Josephson-junction circuits we reconsider decoherence effects in quantum two-level systems (TLS). On one hand, the experiments demonstrate the importance of 1/f noise, on the other hand, by operating at symmetry points one can suppress noise effects in linear order. We, therefore, analyze noise sources with a variety of power spectra, with linear or quadratic coupling, which are longitudinal or transverse relative to the eigenbasis of the unperturbed Hamiltonian. To evaluate the dephasing time for transverse 1/f noise second-order contributions have to be taken into account. Manipulations of the quantum state of the TLS define characteristic time scales. We discuss the consequences for relaxation and dephasing processes.
引用
@article{arxiv.cond-mat/0202518,
title = {Noise and decoherence in quantum two-level systems},
author = {Alexander Shnirman and Yuriy Makhlin and Gerd Schön},
journal= {arXiv preprint arXiv:cond-mat/0202518},
year = {2007}
}
备注
To appear in Proceedings of the Nobel Jubilee Symposium on Condensation and Coherence in Condensed Systems (Physica Scripta)