Dislocation tunnelling in the Peierls-Nabarro potential relief

The theory of quantum mechanical dislocation tunnelling through the Peierls-Nabarro barriers is extended and compared with experimental data on the low temperature plasticity of materials. The behaviour of the flow stress in the range of athermal anomalies is modelled by the change in the mechanism of dislocation motion from the thermoactivated hopping over the barriers to the quantum tunnelling through them.