Journal of Low Temperature Physics

, Volume 105, Issue 1, pp 37–65

Scaling behavior of point contacts between a tungsten tip and the heavy-fermion superconductors

  • K. Gloos
  • F. B. Anders
  • B. Buschinger
  • C. Geibel
  • K. Heuser
  • F. Jährling
  • J. S. Kim
  • R. Klemens
  • R. Müller-Reisener
  • C. Schank
  • G. R. Stewart
Articles

DOI: 10.1007/BF00754627

Cite this article as:
Gloos, K., Anders, F.B., Buschinger, B. et al. J Low Temp Phys (1996) 105: 37. doi:10.1007/BF00754627

Abstract

We investigated metallic point contacts between a tungsten tip and the superconducting heavy-fermion compounds. On lowering the temperature to belowTc the contact resistance drops by δR. Usually this change in resistance is interpreted by the Andreev-reflection process at the normal-superconducting interface. However, we found that δR does not scale with the inverse area of the orifice-as expected for Andreev reflection-but with the inverse radius and the specific resistivity in the normal state. Such a behaviour is characteristic for Maxwell's resistance being suppressed in the superconducting heavy-fermion phase. Additionally, the residual contact resistance at zerobias is strongly enhanced compared to the ballistic Sharvin contribution. We discuss the possible microscopic origin for the reduced or even absent Andreev-hole current and the enhanced residual resistance.

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • K. Gloos
    • 1
  • F. B. Anders
    • 1
    • 2
  • B. Buschinger
    • 1
  • C. Geibel
    • 1
  • K. Heuser
    • 1
  • F. Jährling
    • 1
  • J. S. Kim
    • 3
  • R. Klemens
    • 1
  • R. Müller-Reisener
    • 1
  • C. Schank
    • 1
  • G. R. Stewart
    • 1
    • 4
  1. 1.Institut für FestkörperphysikTechnische Hochschule DarmstadtDarmstadtGermany
  2. 2.Department of PhysicsThe Ohio State UniversityColumbusUSA
  3. 3.Department of PhysicsUniversity of FloridaGainesvilleUSA
  4. 4.Institut für PhysikUniversität AugsburgAugsburgGermany