Dynamics of {sup 3}He impurities in {sup 4}He films

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00753335· OSTI ID:183404

Agnolet, G; Clements, B E ^[1]; Saarela, M ^[2]

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1. Texas A&M Univ., College Station, TX (United States)
2. Univ. of Oulu (Finland); and others

Using a microscopic theory we calculate the binding energy of {sup 3}He impurities in films of {sup 4}He absorbed to a graphite substrate. Without adjustable parameters, we obtain excellent agreement with the experimental binding energies for the ground state of the {sup 3} He impurity. By introducing a time-dependent variational wave function, the impurity atom acquires a hydrodynamic effective mass for its motion parallel to the surface due to hydro-dynamic backflow, and the excited states have a finite lifetime. When these effects are included, both the energy of the first excited state of the impurity, and the effective mass of the ground state, agree well with experimental data. A comparison with recent density functional results is carried out. It is shown that the substrate bound states on strong potentials are spurious and due to the inappropriate treatment of the effective mass within that theory.

• Sponsoring Organization: USDOE
• OSTI ID: 183404
• Report Number(s): CONF-950676--; CNN: Grant DMR-9509743; Grant INT-9014040
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 3-4 Vol. 101; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BINDING ENERGY
GRAPHITE
GROUND STATES
HELIUM
HELIUM 4
IMPURITIES
PHONONS