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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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