Data di Pubblicazione:
2012
Citazione:
Quantized vortices in two dimensional solid 4He / M. Rossi, D. E. Galli, P. Salvestrini, L. Reatto. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6588. - 400:Part.1(2012), pp. 012063.1-012063.4.
Abstract:
Diagonal and off-diagonal properties of 2D solid 4He systems doped with a
quantized vortex have been investigated via the Shadow Path Integral Ground State method
using the fixed-phase approach. The chosen approximate phase induces the standard Onsager-
Feynman flow field. In this approximation the vortex acts as a static external potential and the
resulting Hamiltonian can be treated exactly with Quantum Monte Carlo methods. The vortex
core is found to sit in an interstitial site and a very weak relaxation of the lattice positions
away from the vortex core position has been observed. Also other properties like Bragg peaks
in the static structure factor or the behavior of vacancies are very little affected by the presence
of the vortex. We have computed also the one-body density matrix in perfect and defected
4He crystals finding that the vortex has no sensible effect on the off-diagonal long range tail
of the density matrix. Within the assumed Onsager Feynman phase, we find that a quantized
vortex cannot auto-sustain itself unless a condensate is already present like when dislocations
are present. It remains to be investigated if backflow can change this conclusion.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
M. Rossi, D. E. Galli, P. Salvestrini, L. Reatto
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