Calculation of quantum tunneling for a spatially extended defect: The dislocation kink in copper has a low effective mass

Tejs Vegge, J.P. Sethna, S.-A. Cheong, Karsten Wedel Jacobsen, C.R. Myers, D.C. Ralph

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Abstract

Several experiments indicate that there are atomic tunneling defects in plastically deformed metals. How this is possible has not been clear, given the large mass of the metal atoms. Using a classical molecular-dynamics calculation, we determine the structures, energy barriers, effective masses, and quantum tunneling rates fur dislocation kinks and jogs in copper screw dislocations. We find that jugs are unlikely to tunnel, but the kinks should have large quantum fluctuations. The kink motion involves hundreds of atoms each shifting a tiny amount, leading to a small effective mass and tunneling barrier.
Original languageEnglish
JournalPhysical Review Letters
Volume86
Issue number8
Pages (from-to)1546-1549
ISSN0031-9007
DOIs
Publication statusPublished - 2001

Bibliographical note

Copyright (2001) American Physical Society

Keywords

  • SYSTEMS
  • INSTANTON APPROACH
  • SOLIDS
  • STRESS
  • POLYACETYLENE
  • CRYSTALS
  • SLOW 2-LEVEL FLUCTUATORS
  • METALLIC GLASSES
  • POINT-CONTACT
  • TEMPERATURE

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