Spectrum on elementary excitations in superfluid Bose--Fermi systems

Journal Article · Sat Sep 01 04:00:00 EDT 1973 · Ukr. Fiz. Zh. (Russ. Ed.), v. 18, no. 9, pp. 1439-1447

OSTI ID:4344073

Pashitskii, E A

The spectrum of elementary excitations in the system of interacting Bose- and Fermi-particles was obtained at a temperature of absolute zero (Dose- condensation being taken into account by means of the Bogolyabov canonic transformations. In terms of a model of permeable spheres'' with finite repulsion it(is shown that the boson spectrum omega (p) in a definite region of parameter has the minimum at p = 0. By selecting parameters one succeeds in obtaining a quite satisfactory quantitative agreement of the theoretical and experimental spectra for superfluid helium. In the case when the Fermi energy is considerably higher than the bosorins maximum energy, a gap characterizing bond energy of the copper pairs can appear in the fermion speetrum due to exchange of virtual supercondensate'' bosons. If in this case the interaction between fermions at infinity is of attraction character, then under certain conditions sustained longitudinal collective excitations of Pose-type with a finite gap'' in the energy spectrum may exist in the superfluid fermion subsystem. Possibility of appearance of similar excitations in superfluid nuclear matter of neutron stars (pulsars) due to gravitational interaction between nucleons is discussed. (auth)

• Research Organization: Inst. of Physics, Kiev
• NSA Number: NSA-29-022725
• OSTI ID: 4344073
• Journal Information: Ukr. Fiz. Zh. (Russ. Ed.), v. 18, no. 9, pp. 1439-1447, Journal Name: Ukr. Fiz. Zh. (Russ. Ed.), v. 18, no. 9, pp. 1439-1447; ISSN UFIZA
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

*SUPERFLUIDITY-- EXCITATION
BOSE-EINSTEIN CONDENSATION
ENERGY GAP
HELIUM II
N66100* --Physics (Low Temperature)--Superfluidity