NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Heavy fermion behavior explained by bosonsConventional heavy fermion (HF) theories require existence of massive fermions. We show that heavy fermion phenomena can also be simply explained by existence of bosons with moderate mass but temperature dependent concentration below the formation temperature T(sub B), which in turn is close to room temperature. The bosons B(++) are proposed to be in chemical equilibrium with a system of holes h(+): B(++) = h(+) + h(+). This equilibrium is governed by a boson breaking function f(T), which determines the decreasing boson density and the increasing fermion density with increasing temperature. Since HF-compounds are hybridized from minimum two elements, we assume in addition existence of another fermion component h(sub s)(+) with temperature independent density. This spectator component is thought to be the main agent in binding the bosons in analogy with electronic or muonic molecules. Using a linear boson breaking function we can explain temperature dependence of the giant linear specific heat coefficient gamma(T) coming essentially from bosons. The maxima in resistivity, Hall coefficient, and susceptibility are explained by boson localization effects due to the Wigner crystallization. The antiferromagnetic transitions in turn are explained by similar localization of the pairing fermion system when their density n(sub h)(T(sub FL)) becomes lower than n(sub WC), the critical density of Wigner crystallization. The model applies irrespective whether a compound is superconducting or not. The same model explains the occurrence of low temperature antiferromagnetism also in high-T(sub c) superconductors. The double transition in UPt3 is proposed to be due to the transition of the pairing fermion liquid from spin polarized to unpolarized state.
Document ID
19960000253
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kallio, A.
(Oulu Univ.)
Poykko, S.
(Oulu Univ.)
Apaja, V.
(Oulu Univ.)
Date Acquired
September 6, 2013
Publication Date
April 1, 1995
Publication Information
Publication: NASA. Johnson Space Center, Proceedings of the 4th International Conference and Exhibition: World Congress on Superconductivity, Volume 1
Subject Category
Atomic And Molecular Physics
Accession Number
96N10253
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available