Physical Review B

Diffusion Monte Carlo calculation of rate of elastic transmission of a helium vapor beam through a slab of superfluid helium

Y. Lutsyshyn, J. W. Halleý

Published Jan 12, 2011• 3 citations

Abstract

We present the results of diffusion Monte Carlo calculations of the elastic transmission of a low-energy beam of helium atoms through a suspended slab of superfluid helium. These calculations represent a significant improvement on variational Monte Carlo methods which were previously used to study this problem. The results are consistent with the existence of a condensate-mediated transmission mechanism, which would result in very fast transmission of pulses through a slab.

DOI: 10.1103/physrevb.83.014504

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Physical Review B

Diffusion Monte Carlo calculation of rate of elastic transmission of a helium vapor beam through a slab of superfluid helium

Y. Lutsyshyn, J. W. Halleý

Published Jan 12, 2011• 3 citations

Publisher

Abstract

DOI: 10.1103/physrevb.83.014504

Related papers

Variational Monte Carlo Studies of the Rate of Transmission of an Atomic Helium Beam through a Slab of Superfluid Helium by a Condensate Mediated Process

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We report variational Monte Carlo calculations which give amplitudes and phases of the reflected and transmitted components of states representing scattering of helium atoms normally incident on a superfluid ${}^{4}\mathrm{He}$ slab. The wave function describes a previously postulated condensate mediated process [J. W. Halley et al., Phys. Rev. Lett. 71, 2429 (1993)] and the results are consistent with uncertainty principle arguments suggesting that the transmission time for thin (but macroscopic) samples will be independent of slab thickness.We report variational Monte Carlo calculations which give amplitudes and phases of the reflected and transmitted components of states representing scattering of helium atoms normally incident on a superfluid ${}^{4}\mathrm{He}$ slab. The wave function describes a previously postulated condensate mediated process [J. W. Halley et al., Phys. Rev. Lett. 71, 2429 (1993)] and the results are consistent with uncertainty principle arguments suggesting that the transmission time for thin (but macroscopic) samples will be independent of slab thickness.

Physical Review LettersNov 17, 199718 citations

Variational calculations of coupling of an incident helium atom to a slab of superfluid helium four

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Physical Review LettersOct 11, 199337 citations

{}^{4}\mathrm{He}

slab. The wave function describes a previously postulated condensate mediated process [J. W. Halley et al., Phys. Rev. Lett. 71, 2429 (1993)] and the results are consistent with uncertainty principle arguments suggesting that the transmission time for thin (but macroscopic) samples will be independent of slab thickness.

We show that very low velocity droplets can be used to carry out an experiment to test whether condensate mediated transmission processes can occur in a superfluid droplet of

^{4}\mathrm{He}

. By appropriately choosing the droplet radius and temperature, we can eliminate the competing roton, phonon, and ripplon mediated elastic transmission events. Then a calculation shows that if a few percent or more of the incident atoms experience anomalous condensate mediated transmission, the effects should be detectable in the droplet trajectories. We consider two forms of the experiment, involving a freely falling droplet in ambient vapor in the first instance and an oscillating droplet in a magnetic trap in the second.

{\mathit{A}}^{2}

(first process) and

{\mathit{A}}^{4}

(second process), respectively, for small A. Aspects of a fully many body calculation and the performance of such an experiment are briefly discussed.