We propose and study a model of dephasing due to an environment of bistable fluctuators. We apply our analysis to the decoherence of Josephson qubits, induced by background charges present in the substrate, which are also responsible for the 1/f noise. The discrete nature of the environment leads to a number of new features which are mostly pronounced for slowly moving charges. Far away from the degeneracy this model for the dephasing is solved exactly.

arXiv:cond-mat/0201449Physical Review LettersMay 20, 2002326 citations

Decoherence of a Josephson qubit due to coupling to two-level systems

Li-Chung Ku, Clare C. Yu

arXiv:cond-mat/0409006Physical Review BJul 18, 200555 citations

Advances in solid state physics

Decoherence Due to Discrete Noise in Josephson Qubits

Elisabetta Paladino, Lara Faoro, G. Falci

Published Jul 29, 2003• 31 citations

Publisher

DOI: 10.1007/978-3-540-44838-9_53

Related papers

Decoherence and 1/f noise in Josephson qubits

Elisabetta Paladino, Lara Faoro, Antonio D’Arrigo +1 more

arXiv:cond-mat/0312411Physica E Low-dimensional Systems and NanostructuresMar 25, 200324 citations

Quantum control of discrete noise in Josephson qubits

Antonio D’Arrigo, G. Falci, Andrea Mastellone +1 more

Physica E Low-dimensional Systems and NanostructuresJul 6, 20059 citations

Decoherence In Flux Qubits Due to 1/f Noise in Josephson Junctions

Dale J. Van Harlingen, B. L. T. Plourde, Timothy L. Robertson +2 more

Springer eBooksJan 1, 20046 citations

Short-time decoherence of Josephson charge qubits in Ohmic and 1/f noise environment

Xian-Ting Liang

arXiv:quant-ph/0503155Physica C SuperconductivityOct 11, 20055 citations

Decoherence and 1/f Noise in Josephson Qubits

Elisabetta Paladino, Lara Faoro, G. Falci +1 more

arXiv:cond-mat/0201449Physical Review LettersMay 20, 2002326 citations

Decoherence of a Josephson qubit due to coupling to two-level systems

Li-Chung Ku, Clare C. Yu

Noise and decoherence are major obstacles to the implementation of Josephson junction qubits in quantum computing. Recent experiments suggest that two-level systems (TLS) in the oxide tunnel barrier are a source of decoherence. We explore two decoherence mechanisms in which these two-level systems lead to the decay of Rabi oscillations that result when Josephson junction qubits are subjected to strong microwave driving. (A) We consider a Josephson qubit coupled resonantly to a two-level system, i.e., the qubit and TLS have equal energy splittings. As a result of this resonant interaction, the occupation probability of the excited state of the qubit exhibits beating. Decoherence of the qubit results when the two-level system decays from its excited state by emitting a phonon. (B) Fluctuations of the two-level systems in the oxide barrier produce fluctuations and $1∕f$ noise in the Josephson junction critical current ${I}_{0}$ . This in turn leads to fluctuations in the qubit energy splitting that degrade the qubit coherence. We compare our results with experiments on Josephson junction phase qubits.Noise and decoherence are major obstacles to the implementation of Josephson junction qubits in quantum computing. Recent experiments suggest that two-level systems (TLS) in the oxide tunnel barrier are a source of decoherence. We explore two decoherence mechanisms in which these two-level systems lead to the decay of Rabi oscillations that result when Josephson junction qubits are subjected to strong microwave driving. (A) We consider a Josephson qubit coupled resonantly to a two-level system, i.e., the qubit and TLS have equal energy splittings. As a result of this resonant interaction, the occupation probability of the excited state of the qubit exhibits beating. Decoherence of the qubit results when the two-level system decays from its excited state by emitting a phonon. (B) Fluctuations of the two-level systems in the oxide barrier produce fluctuations and $1∕f$ noise in the Josephson junction critical current ${I}_{0}$. This in turn leads to fluctuations in the qubit energy splitting that degrade the qubit coherence. We compare our results with experiments on Josephson junction phase qubits.

arXiv:cond-mat/0409006Physical Review BJul 18, 200555 citations

1∕f

noise in the Josephson junction critical current

{I}_{0}

. This in turn leads to fluctuations in the qubit energy splitting that degrade the qubit coherence. We compare our results with experiments on Josephson junction phase qubits.