Anisotropy of the superconducting energy gap in URuuSi2 studied by point-contact spectroscopy
Physikalisches Institut Universität Karlsruhe - 76128 Karlsruhe, Germany
2 Institute for Low Temperature Physics and Engineering, Academy of Science of Ukraine, 310164 Kharkov, Ukraine
3 Van der Waals-Zeeman Laboratorium, Universiteit van Amsterdam, 1018 XE Amsterdam, The Netherlands
Accepted: 19 January 1996
The differential resistance vs. applied voltage V for –normal-metal point-contacts (PCs) is investigated. For some PCs a clear double-minimum structure is observed in vs. V at zero bias well below the superconducting critical temperature Tc as expected for the Andreev reflection. The double minimum occurs only for PCs with suppressed antiferromagnetic (AF) features in , in support of a recent model of the gap depression by AF order in the (a,b)-plane of tetragonal . A strong anisotropy of the reduced gap 2 and of for PCs along the a and the c axis is also observed.
PACS: 74.70.Tx – Heavy-fermion superconductors / 73.40.Jn – Metal-to-metal contacts / 74.70.-b – Superconducting materials (excluding high-Tc cuprates)
© EDP Sciences, 1996