Point -contact Andreev reflection spectroscopy of heavy-fermion-metal/superconductor junctions

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Physica B

DOI:https://doi.org/10.1016/j.physb.2007.10.229· OSTI ID:974446

Park, W; Stalzer, H; Sarrao, J; Thompson, J; Pham, L; Fisk, Z; Frederick, J; Canfield, P; Greene, L

Our previous point-contact Andreev reflection studies of the heavy-fermion superconductor CeCoIn{sub 5} using Au tips have shown two clear features: reduced Andreev signal and asymmetric background conductance. To explore their physical origins, we have extended our measurements to point-contact junctions between single crystalline heavy-fermion metals and superconducting Nb tips. Differential conductance spectra are taken on junctions with three heavy-fermion metals, CeCoIn{sub 5}, CeRhIn{sub 5}, and YbAl{sub 3}, each with different electron mass. In contrast with Au/CeCoIn{sub 5} junctions, Andreev signal is not reduced and no dependence on effective mass is observed. A possible explanation based on a two-fluid picture for heavy fermions is proposed.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC02-07CH11358
• OSTI ID: 974446
• Report Number(s): IS-J 7414; TRN: US1002322
• Journal Information: Physica B, Vol. 403, Issue 5-9
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EFFECTIVE MASS
ELECTRONS
FERMIONS
REFLECTION
SPECTRA
SPECTROSCOPY
SUPERCONDUCTORS