Inhomogeneous broadening and the Kosterlitz-Thouless transition. Academic Article uri icon


  • Torsional-oscillator studies of very thin He4 films have found nonuniversal behavior of the superfluid response as a function of coverage. The temperature width of the superfluid transition region is nonmonotonic in the areal density n and exhibits cusplike variations at half of the layering period. We explore the assumption that this additional broadening is caused by macroscopic inhomogeneities in the substrate potential; such a theory for inhomogeneous broadening can be constructed from the Kosterlitz-Nelson relation between the superfluid areal density ns and the transition temperature Tc by determining the theoretical ''sensitivity'' S of ns to variations in the strength of the substrate potential. For substrate models that are atomically uniform, a simple microscopic hypernetted-chain calculation (without either ''elementary diagrams'' or three-body correlations, but with an optimized Jastrow function) finds this sensitivity always to be of the same sign, and yields reasonable order-of-magnitude agreement with experiment. However, models for which the sensitivity does not change sign appear to be incapable of yielding either the cusps or the half-periodicity of the data. We suggest that these properties may occur with a more recently developed (and more sophisticated) version of hypernetted-chain theory, wherein "elementary diagrams" and three-body correlations are incorporated. 1993 The American Physical Society.

published proceedings

  • Phys Rev B Condens Matter

author list (cited authors)

  • Collins, M., Agnolet, G., Saslow, W. M., & Krotscheck, E.

citation count

  • 3

complete list of authors

  • Collins, M||Agnolet, G||Saslow, WM||Krotscheck, E

publication date

  • April 1993