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

W. K. Park; H. Stalzer; J. L. Sarrao; J. D. Thompson; L. D. Pham; Z. Fisk; J. Frederick; P. C. Canfield; L. H. Greene

doi:10.1016/j.physb.2007.10.229

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

W. K. Park, H. Stalzer, J. L. Sarrao, J. D. Thompson, L. D. Pham, Z. Fisk, J. Frederick, P. C. Canfield, L. H. Greene

Research output: Contribution to journal › Article › peer-review

Abstract

Our previous point-contact Andreev reflection studies of the heavy-fermion superconductor CeCoIn₅ 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, CeCoIn₅, CeRhIn₅, and YbAl₃, each with different electron mass. In contrast with Au/CeCoIn₅ 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.

Original language	English (US)
Pages (from-to)	818-819
Number of pages	2
Journal	Physica B: Condensed Matter
Volume	403
Issue number	5-9
DOIs	https://doi.org/10.1016/j.physb.2007.10.229
State	Published - Apr 1 2008
Externally published	Yes

Keywords

Andreev reflection
Blonder-Tinkham-Klapwijk theory
Effective mass
Heavy fermions

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics

Online availability

10.1016/j.physb.2007.10.229

Library availability

Discover UIUC Full Text

Cite this

@article{df9b40394ba34eaa859fb5ad7d1f273f,

title = "Point-contact Andreev reflection spectroscopy of heavy-fermion-metal/superconductor junctions",

abstract = "Our previous point-contact Andreev reflection studies of the heavy-fermion superconductor CeCoIn5 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, CeCoIn5, CeRhIn5, and YbAl3, each with different electron mass. In contrast with Au/CeCoIn5 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.",

keywords = "Andreev reflection, Blonder-Tinkham-Klapwijk theory, Effective mass, Heavy fermions",

author = "Park, {W. K.} and H. Stalzer and Sarrao, {J. L.} and Thompson, {J. D.} and Pham, {L. D.} and Z. Fisk and J. Frederick and Canfield, {P. C.} and Greene, {L. H.}",

year = "2008",

month = apr,

day = "1",

doi = "10.1016/j.physb.2007.10.229",

language = "English (US)",

volume = "403",

pages = "818--819",

journal = "Physica B: Condensed Matter",

issn = "0921-4526",

publisher = "Elsevier",

number = "5-9",

}

TY - JOUR

T1 - Point-contact Andreev reflection spectroscopy of heavy-fermion-metal/superconductor junctions

AU - Park, W. K.

AU - Stalzer, H.

AU - Sarrao, J. L.

AU - Thompson, J. D.

AU - Pham, L. D.

AU - Fisk, Z.

AU - Frederick, J.

AU - Canfield, P. C.

AU - Greene, L. H.

PY - 2008/4/1

Y1 - 2008/4/1

N2 - Our previous point-contact Andreev reflection studies of the heavy-fermion superconductor CeCoIn5 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, CeCoIn5, CeRhIn5, and YbAl3, each with different electron mass. In contrast with Au/CeCoIn5 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.

AB - Our previous point-contact Andreev reflection studies of the heavy-fermion superconductor CeCoIn5 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, CeCoIn5, CeRhIn5, and YbAl3, each with different electron mass. In contrast with Au/CeCoIn5 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.

KW - Andreev reflection

KW - Blonder-Tinkham-Klapwijk theory

KW - Effective mass

KW - Heavy fermions

UR - http://www.scopus.com/inward/record.url?scp=39749197422&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=39749197422&partnerID=8YFLogxK

U2 - 10.1016/j.physb.2007.10.229

DO - 10.1016/j.physb.2007.10.229

M3 - Article

AN - SCOPUS:39749197422

SN - 0921-4526

VL - 403

SP - 818

EP - 819

JO - Physica B: Condensed Matter

JF - Physica B: Condensed Matter

IS - 5-9

ER -

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

Abstract

Keywords

ASJC Scopus subject areas

Online availability

Library availability

Related links

Fingerprint

Cite this