Microscopic charged fluctuators as a limit to the coherence of disordered superconductor devices

Autor:	Sueur, Hélène le, Svilans, Artis, Bourlet, Nicolas, Murani, Anil, Bergé, Laurent, Dumoulin, Louis, Joyez, Philippe
Rok vydání:	2018
Předmět:	Condensed Matter - Superconductivity Condensed Matter - Mesoscale and Nanoscale Physics
Druh dokumentu:	Working Paper
Popis:	By performing experiments with thin-film resonators of NbSi, we elucidate a decoherence mechanism at work in disordered superconductors. This decoherence is caused by charged Two Level Systems (TLS) which couple to the conduction electrons in the BCS ground state; it does not involve any out-of-equilibrium quasiparticles, vortices, etc. Standard theories of mesoscopic disordered conductors enable making predictions regarding this mechanism, notably that decoherence should increase as the superconductor cross section decreases. Given the omnipresence of charged TLS in solid-state systems, this decoherence mechanism affects, to some degree, all experiments involving disordered superconductors. In particular, we show it easily explains the poor coherence observed in quantum phase slip experiments and may contribute to lowering the quality factors in some disordered superconductor resonators. Comment: 13 pages, 2 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1810.12801 Zobrazit plný text záznamu View this record from Arxiv