Thermal conductivity of the accidental degeneracy and enlarged symmetry group models for superconducting UPt{sub 3}

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1023/A:1021814206687· OSTI ID:320961

Graf, M J ^[1]; Yip, S K; Sauls, J A ^[1]

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1. Northwestern Univ., Evanston, IL (United States). Dept. of Physics and Astronomy

The authors present theoretical calculations of the thermal conductivity for the accidental degeneracy and enlarged symmetry group models that have been proposed to explain the phase diagram of UPt{sub 3}. The order parameters for these models possess point nodes or cross nodes, reflecting the broken symmetries of the ground state. These broken symmetries lead to robust predictions for the ratio of the low-temperature thermal conductivity for heat flow along the {cflx c} axis and in the basal plane. The anisotropy of the heat current response at low temperatures is determined by the phase space for scattering by impurities. The measured anisotropy ratio, {kappa}{sub c}/{kappa}{sub b}, provides a strong constraint on theoretical models for the ground state order parameter. The accidental degeneracy and enlarged symmetry group models based on no spin-orbit coupling do not account for the thermal conductivity of UPt{sub 3}. The models for the order parameter that fit the experimental data for the {cflx c} and {cflx b} directions of the heat current are the 2D E{sub 1g} and E{sub 2u} models, for which the order parameters possess line nodes in the ab-plane and point nodes along the {cflx c} axis, and the A{sub 1g} {circle_plus} E{sub 1g} model of Zhitomirsky and Ueda. This model spontaneously breaks rotational symmetry in the ab-plane below T{sub c2} and predicts a large anisotropy for the ab-plane heat current.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• OSTI ID: 320961
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 1-2 Vol. 114; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
MATHEMATICAL MODELS
ORDER PARAMETERS
PLATINUM BASE ALLOYS
SUPERCONDUCTIVITY
SYMMETRY BREAKING
THERMAL CONDUCTIVITY
URANIUM ALLOYS