Calculation of quantum tunneling for a spatially extended defect : the dislocation kink in copper has a low effective mass
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...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
2009
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/91723 http://hdl.handle.net/10220/4592 http://sfxna09.hosted.exlibrisgroup.com:3410/ntu/sfxlcl3?sid=metalib:CSA_MEDLINE&id=doi:&genre=&isbn=&issn=0031-9007&date=2001&volume=86&issue=8&spage=1546&epage=9&aulast=Vegge&aufirst=%20T&auinit=&title=Physical%20review%20letters&atitle=Calculation%20of%20quantum%20tunneling%20for%20a%20spatially%20extended%20defect%3A%20the%20dislocation%20kink%20in%20copper%20has%20a%20low%20effective%20mass%2E |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Nanyang Technological University |
| Language: | English |
| Summary: | 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 for dislocation kinks and jogs in copper screw dislocations. We find that jogs 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. |
|---|