Superfluidity of bosons on a deformable lattice

Physics – Condensed Matter – Superconductivity

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

12 pages, 14 figures, to appear in Phys. Rev. B

Scientific paper

10.1103/PhysRevB.63.184512

We study the superfluid properties of a system of interacting bosons on a lattice which, moreover, are coupled to the vibrational modes of this lattice, treated here in terms of Einstein phonon model. The ground state corresponds to two correlated condensates: that of the bosons and that of the phonons. Two competing effects determine the common collective soundwave-like mode with sound velocity $v$, arising from gauge symmetry breaking: i) The sound velocity $v_0$ (corresponding to a weakly interacting Bose system on a rigid lattice) in the lowest order approximation is reduced due to reduction of the repulsive boson-boson interaction, arising from the attractive part of phonon mediated interaction in the static limit. ii) the second order correction to the sound velocity is enhanced as compared to the one of bosons on a rigid lattice when the the boson-phonon interaction is switched on due to the retarded nature of phonon mediated interaction. The overall effect is that the sound velocity is practically unaffected by the coupling with phonons, indicating the robustness of the superfluid state. The induction of a coherent state in the phonon system, driven by the condensation of the bosons could be of experimental significance, permitting spectroscopic detections of superfluid properties of the bosons. Our results are based on an extension of the Beliaev - Popov formalism for a weakly interacting Bose gas on a rigid lattice to that on a deformable lattice with which it interacts.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Superfluidity of bosons on a deformable lattice does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Superfluidity of bosons on a deformable lattice, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Superfluidity of bosons on a deformable lattice will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-301291

All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.