Nonlocal Nonlinear Schrödinger Equations as Models of Superfluidity

  title={Nonlocal Nonlinear Schr{\"o}dinger Equations as Models of Superfluidity},
  author={Natalia G. Berloff},
  journal={Journal of Low Temperature Physics},
Condensate models for superfluid helium II with nonlocal potentials are considered. The potentials are chosen so that the models give a good fit to the Landau dispersion curve; i.e., the plot of quasi-particle energy E versus momentum p has the correct slope at the origin (giving the correct sound velocity) and the roton minimum is close to that experimentally observed. It is shown that for any such potential the condensate model has non-physical features, specifically the development of… CONTINUE READING