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arXiv · 1212.6419

Phase diagram of $^{4}$He on graphene

Jodok Happacher·Philippe Corboz·Massimo Boninsegni·Lode Pollet
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Abstract

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) $Å^{-2}$. 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.

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Jodok Happacher, Philippe Corboz, Massimo Boninsegni, Lode Pollet. 2013-06-03. Phase diagram of $^{4}$He on graphene. https://doi.org/10.1103/physrevb.87.094514

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