Point-contact spectroscopy on the heavy-fermion superconductor UPt3 in thenormal and superconducting states

Citation
G. Goll et H. Von Lohneysen, Point-contact spectroscopy on the heavy-fermion superconductor UPt3 in thenormal and superconducting states, PHYSICA C, 318, 1999, pp. 82-88
Citations number
39
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA C
ISSN journal
09214534 → ACNP
Volume
318
Year of publication
1999
Pages
82 - 88
Database
ISI
SICI code
0921-4534(199905)318:<82:PSOTHS>2.0.ZU;2-8
Abstract
The heavy-fermion superconductor UPt3 has been investigated by point-contac t spectroscopy in the normal and superconducting state with Pt as a normal- metal counterelectrode. In the normal state well above T-c, the spectra, i. e., the differential resistance dV/dI as a function of applied bias voltage V, are determined by the thermal transport regime and can be described by the heating model. Close to and below T-c diffusive or even ballistic trans port through the contact yields voltage (i.e. energy) dependent non-lineari ties of the point-contact characteristics. Andreev reflection (AR) of quasi particles at the UPt3-Pt interface probes the superconducting energy gap an d its complex angular structure. The results support that the anomalous sup erconductivity in UPt3 can be attributed to the presence of a two-dimension al (2D) order parameter (OP) with point and line nodes. (C) 1999 Elsevier S cience B.V. All rights reserved.