Quantum mechanical approach to the velocity of dislocations in ice

A quantum mechanical formulation is used to calculate the velocity of a kink on an otherwise straight dislocation line in ice. Treating the kink as a quasi-particle there exists the probability that it can tunnel through the potential barrier caused by unfavorable positions of the protons on the site just ahead of it. By unfavorable it is meant that the protons are arranged such that point defects occur if the kink proceeds. When an external stress is applied to the system there will be a net drift of the kink which advances the dislocation. The drift velocity thus calculated is in agreement with experimental evidence