A transition, from thermally activated to athermal, plastic flow was observed at temperatures near to, and below, 1K. It was concluded that this low-temperature plasticity anomaly was a characteristic feature of quantum processes.

Quantum Motion of Dislocation in Single Crystals of Tin at Temperatures Near 0.5K. V.V.Pustovalov, V.D.Natsik, G.I.Kirichenko, V.P.Soldatov, S.E.Shumilin: Physica B, 2000, 284-288, 1253-4