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Evidence for coherent quantum phase slips across a Josephson junction array
- Source :
- Physical Review B. 85
- Publication Year :
- 2012
- Publisher :
- American Physical Society (APS), 2012.
-
Abstract
- Superconducting order in a sufficiently narrow and infinitely long wire is destroyed at zero temperature by quantum fluctuations, which induce $2\pi$ slips of the phase of the order parameter. However, in a finite-length wire coherent quantum phase-slips would manifest themselves simply as shifts of energy levels in the excitations spectrum of an electrical circuit incorporating this wire. The higher the phase-slips probability amplitude, the larger are the shifts. Phase-slips occurring at different locations along the wire interfere with each other. Due to the Aharonov-Casher effect, the resulting full amplitude of a phase-slip depends on the offset charges surrounding the wire. Slow temporal fluctuations of the offset charges make the phase-slips amplitudes random functions of time, and therefore turn energy levels shifts into linewidths. We experimentally observed this effect on a long Josephson junction array acting as a "slippery" wire. The slip-induced linewidths, despite being only of order 100 kHz, were resolved from the flux-dependent dephasing of the fluxonium qubit.<br />Comment: 15 pages
- Subjects :
- Quantum phase transition
Physics
Josephson effect
Quantum Physics
Condensed Matter - Mesoscale and Nanoscale Physics
Condensed matter physics
Condensed Matter - Superconductivity
Quantum wire
Dephasing
FOS: Physical sciences
Order (ring theory)
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Condensed Matter Physics
01 natural sciences
010305 fluids & plasmas
Electronic, Optical and Magnetic Materials
Superconductivity (cond-mat.supr-con)
Pi Josephson junction
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
0103 physical sciences
Quantum Physics (quant-ph)
010306 general physics
Energy (signal processing)
Long Josephson junction
Subjects
Details
- ISSN :
- 1550235X and 10980121
- Volume :
- 85
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi.dedup.....9902e86f2233eaec1f5a9410a827ea68