QFS2016 Book of Abstracts

Abstracts

P1.33 Quantum Monte Carlo study of Mg-doped bulk helium-4 Yaroslav Lutsyshyn Institut f¨ur Physik, University of Rostock, Germany

Mg-doped helium droplets are believed to have an observable metastable state in which the alkali atoms remain separated by a considerable distance, thus forming so-called “atomic foam”. The exact nature of such a state is not well understood. We will describe our efforts to study the confinement-induced long-distance interaction between a pair of Mg atoms suspended in the superfluid. P1.34 NMR study of interactions in 3 He- 4 He mixture films on graphite. A. Waterworth(1), J. Nyeki(1), B. Cowan(1), J. Saunders(1) 1) Department of Physics, Royal Holloway, University of London, UK Layered 3 He- 4 He fluid mixture films on graphite provide a model 2D Fermi system, which is tuned by changing either the 3 He or 4 He surface density. We report preliminary SQUID NMR measurements, at temperatures down to 250 µ K, for 3 He on a three layer 4 He film. For 3 He coverages 1 ≤ n3 ≤ 4 nm − 2 , the data allow comparison with Fermi gas theory. At higher 3 He coverages (n3 ≥ 5.0 nm − 2 ) population of the first excited surface Andreev bound state leads to a more complex temperature dependent magnetization, arising from a change in structure of the 4 He fluid layer. The magnetization at low 3 He densities (n3 ≤ 1.0 nm − 2 ) will also be discussed, in terms of interactions mediated by the 4 He layer.

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