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Title: Quantum ground state effect on fluctuation rates in nano-patterned superconducting structures

In this Letter, we present a theoretical model with experimental verifications to describe the abnormal behaviors of the measured fluctuation rates occurring in nano-patterned superconducting structures below the critical temperature. In the majority of previous works, it is common to describe the fluctuation rate by defining a fixed ground state or initial state level for the singularities (vortex or vortex-antivortex pairs), and then employing the well-known rate equations to calculate the liberation rates. Although this approach gives an acceptable qualitative picture, without utilizing free parameters, all the models have been inadequate in describing the temperature dependence of the rate for a fixed width or the width dependence of the rate for a fixed temperature. Here, we will show that by defining a current-controlled ground state level for both the vortex and vortex-antivortex liberation mechanisms, the dynamics of these singularities are described for a wide range of temperatures and widths. According to this study, for a typical strip width, not only is the vortex-antivortex liberation higher than the predicted rate, but also quantum tunneling is significant in certain conditions and can not be neglected.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [2] ;  [5] ;  [2]
  1. Institute for Quantum Computing, University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1 (Canada)
  2. (Canada)
  3. Harvard University, Cambridge, Massachusetts 02138 (United States)
  4. University of British Columbia, 2329 West Mall Vancouver, British Columbia V6T 1Z4 Canada (Canada)
  5. (United States)
Publication Date:
OSTI Identifier:
22253797
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRITICAL TEMPERATURE; FLUCTUATIONS; GROUND STATES; REACTION KINETICS; SINGULARITY; TEMPERATURE DEPENDENCE; TUNNEL EFFECT; VORTICES; WIDTH