Lifetime and coherence of two-level defects in a Josephson junction
| Autor: | John M. Martinis, Yoni Shalibo, Yaara Rofe, Matthew Neeley, Felix Zeides, David Shwa, Nadav Katz |
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| Rok vydání: | 2010 |
| Předmět: |
Physics
Josephson effect Quantum Physics Quantum decoherence Condensed matter physics Phonon Condensed Matter - Superconductivity FOS: Physical sciences General Physics and Astronomy Superconductivity (cond-mat.supr-con) Phase qubit Pi Josephson junction Qubit Superconducting tunnel junction Quantum Physics (quant-ph) Coherence (physics) |
| Zdroj: | Physical review letters. 105(17) |
| ISSN: | 1079-7114 |
| Popis: | We measure the lifetime ($T_{1}$) and coherence ($T_{2}$) of two-level defect states (TLSs) in the insulating barrier of a Josephson phase qubit and compare to the interaction strength between the two systems. We find for the average decay times a power law dependence on the corresponding interaction strengths, whereas for the average coherence times we find an optimum at intermediate coupling strengths. We explain both the lifetime and the coherence results using the standard TLS model, including dipole radiation by phonons and anti-correlated dependence of the energy parameters on environmental fluctuations. 4 pages, 4 figures and supplementary material (3 pages, 2 figures, 1 table) |
| Databáze: | OpenAIRE |
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