Superfluidity transition of a two-dimensional Bose-gas

Project Information

Grant agreement ID: INTAS-RFBR95-0658

Start date

End date

Funded under

• International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993-

Total cost No data

EU contribution No data

Coordinated by

University of Turku
Finland

Objective

The project is intended to observe the superfluidity transition of spin-polarized atomic hydrogen adsorbed on the surface of liquid helium and to study elementary processes in such a weakly interacting two-dimensional Bose gas in the vicinity of and at the transition region. In order to achieve the required high surface densities of H atoms at temperatures below 200 mK, a small portion of the sample will be compressed into the potential well formed on the surface of superfluid helium by the highly inhomogeneous magnetic field at the end of a thin-walled tubular field intensifier. A bolometric measurement of the heat liberated in NMR-induced exchange recombinations will be employed to determine the surface density and to detect the appearance of the two-dimensional superfluid H component.

The project proposed here is encouraged by preliminary experiments carried out in 1994 where two-dimensional H was compressed magnetically to about half of the superfluid surface density. Then the compressed gas fraction was yet too large, 300 microns in diameter, to render a sufficiently effective extraction of recombination heat from it. In the proposed work the characteristic dimension of the densest H will be reduced by an order of magnitude and bulk superfluid He-4 will be used as adsorbate. Then the sample will not be excessively overheated.

The influence of the quasi-condensate formation on dipole-dipole interactions of H atoms will be studied by monitoring the heat liberated in recombinations induced by 190 GHz ESR directly in the compressed H. The dependence of heat exchange processes in surface-adsorbed H on the thickness of undersaturated helium-film substrate will also be investigated as well as the influence of the superfluid H component on the interaction between H atoms and undersaturated He films.

The results of this project are anticipated to be of such importance that they can be published in high-impact international scientific journals and emanated also in international meetings.

Programme(s)

• IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993-

Topic(s)

• 1 - Physics, Astronomy, Astrophysics

Call for proposal

Data not available

Funding Scheme

Data not available

Coordinator

University of Turku

• EU contribution: No data
• Address: 20014 Turku ; Finland
• Total cost: No data

Participants (1)

Russian Research Centre I.V. Kurchatov Institute

Russia

• EU contribution: No data
• Address: 123182 Moscow
• Total cost: No data