Scaling behavior of point contacts between a tungsten tip and the heavy-fermion superconductors
- Institut fuer Festkoerperphysik, Darmstadt (Germany); and others
The authors investigated metallic point contacts between a tungsten tip and the superconducting heavy-fermion compounds. On lowering the temperature to below T{sub c} the contact resistance drops by {delta}R. Usually this change in resistance is interpreted by the Andreev-reflection process at the normal-superconducting interface. However, the authors found that {delta}R 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 zero-bias is strongly enhanced compared to the ballistic Sharvin contribution. They discuss the possible microscopic origin for the reduced or even absent Andreev-hole current and the enhanced residual resistance.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 482488
- Journal Information:
- Journal of Low Temperature Physics, Vol. 105, Issue 1-2; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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