Aubry transition in a real material:: Prediction for its existence in an incommensurate gold/gold interface

Recent studies have shown that a special grain boundary in gold is stable and is an incommensurate interface related to the irrational number root2. Using the theoretical framework of quasicrystals, we show that this system can undergo an Aubry transition: the two grains can glide freely along the ideal interface; if we increase the interactions between the grains by applying a compression perpendicular to the interface, there is a threshold after which the grains are pinned to each other. With a numerical analysis of the energy landscape corresponding to the shift of the grains, we determine the atomistic mechanism of the grain sliding.