Calculation of quantum tunneling for a spatially extended defect : the dislocation kink in copper has a low effective mass
Sethna, James. P.
Cheong, Siew Ann
Jacobsen, K. W.
Myers, Christopher R.
Ralph, Daniel C.
Date of Issue2001
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.
DRNTU::Science::Physics::Atomic physics::Solid state physics
Physical review letters
Physical Review Letters. © 2001 The American Physical Society. The journal's website is located at http://www.aps.org/