Hamburg 2009 – scientific programme

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A: Fachverband Atomphysik

A 15: Poster I

A 15.32: Poster

Tuesday, March 3, 2009, 16:30–19:00, VMP 9 Poster

Local superfluidity in finite 2D helium systems — •Jens Böning, Alexei Filinov, and Michael Bonitz — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts Universität, Kiel, Germany

It was shown previously[1], that the superfluid density vanishes non-homogeneously upon density induced freezing in harmonically trapped 2D systems of charged bosons. While the total superfluid fraction declines, the radial distribution of the superfluid density becomes localized either in the core or at the boundary of the system. Our investigations revealed that the driving mechanism behind this behavoir is related to the hexagonal ordering in the system. In this work we extend our analysis to 2D systems of trapped helium atoms. We consider two kinds of trapping, firstly a harmonic trap as used in our Coulomb systems, and secondly a hard wall confinement. We employ the path-integral Monte-Carlo method with worm algorithm extension[2] for our simulations which requires no approximations on interaction potentials.

[1] A. Filinov, J. Böning, M. Bonitz, and Yu. Lozovik, Phys. Rev. B 77, 214527 (2008)

[2] M. Boningsegni, N. V. Prokof’ev, and B. V. Svistunov, Phys. Rev. E 74, 036701 (2006)