Dislocation Kinks in Copper: Widths, Barriers, Effective Masses, and   Quantum Tunneling
  We calculate the widths, migration barriers, effective masses, and quantum tunneling rates of kinks and jogs in extended screw dislocations in copper, using an effective medium theory interatomic potential. The energy barriers and effective masses for moving a unit jog one lattice constant are close to typical atomic energies and masses: tunneling will be rare. The energy barriers and effective masses for the motion of kinks are unexpectedly small due to the spreading of the kinks over a large number of atoms. The effective masses of the kinks are so small that quantum fluctuations will be important. We discuss implications for quantum creep, kink--based tunneling centers, and Kondo resonances. 
Tejs Vegge, James P. Sethna, Siew-Ann Cheong, Karsten W. Jacobsen,   Christopher R. Myers, and Daniel C. Ralph