Tuesday, January 1, 2013

1212.6419 (Jodok Happacher et al.)

Phase diagram of $^{4}$He on graphene    [PDF]

Jodok Happacher, Philippe Corboz, Massimo Boninsegni, Lode Pollet
The low temperature phase diagram of $^4$He adsorbed on a single graphene sheet is studied by computer simulation of a system comprising nearly thousand helium atoms. In the first layer, two commensurate solid phases are observed, with fillings 1/3 and 7/16 respectively, separated by a domain wall phase, as well as an incommensurate crystal at higher coverage. No evidence of a thermodynamically stable superfliuid phase is found for the first adlayer. Second layer promotion occurs at a coverage of 0.111(4) $\AA^{-2}$. In the second layer two phases are observed, namely a superfluid and an incommensurate solid, with no commensurate solid intervening between these two phases. The computed phase diagram closely resembles that predicted for helium on graphite.
View original: http://arxiv.org/abs/1212.6419

No comments:

Post a Comment