2002/01/01 by Alexander Shnirman, Yuriy Makhlin, Gerd Schön +1 · 1 citation
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.mes-hall #cond-mat.supr-con #quant-ph
paper · pdf · doi:10.1238/physica.topical.102a00147
published as Physica Scripta T102, 147-154 (2002) · To appear in Proceedings of the Nobel Jubilee Symposium on Condensation and Coherence in Condensed Systems (Physica Scripta)
openalex publication_date 2002/01/01 · arxiv created 2002/02/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
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.