Finite size Berezinski-Kosterlitz-Thouless transition at grain boundaries in solid ${}^4$He and role of ${}^3$He impurities

S. Gaudio, E. Cappelluti, G. Rastelli +1

We analyze the complex phenomenology of the Non-Classical Rotational Inertia (NCRI) observed at low temperature in solid ${}^4$He within the context of a two dimensional Berezinski-K…