Superconductivity in an almost localized Fermi liquid of quasiparticles with spin-dependent masses and effective-field induced by electron correlations

作     者：Jan Kaczmarczyk Jozef Spałek 

作者机构：Marian Smoluchowski Institute of Physics Jagiellonian University ul. Reymonta 4 30-059 Kraków Poland Faculty of Physics and Applied Computer Science AGH University of Science and Technology ul. Reymonta 19 30-059 Kraków Poland 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2009年第79卷第21期

页      面：214519-214519页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：cerium compounds cobalt compounds Cooper pairs effective mass electron correlations Fermi liquid heavy fermion superconductors 

摘      要：Paired state of nonstandard quasiparticles is analyzed in detail in two model situations. Namely, we consider the Cooper-pair bound state and the condensed phase of an almost localized Fermi liquid composed of quasiparticles in a narrow band with the spin-dependent masses and an effective field, both introduced earlier and induced by strong electronic correlations. Each of these novel characteristics is calculated in a self-consistent manner. We analyze the bound states as a function of Cooper-pair momentum |Q| in applied magnetic field in the strongly Pauli limiting case (i.e., when the orbital effects of applied magnetic field are disregarded). The spin-direction dependence of the effective mass makes the quasiparticles comprising Cooper-pair spin distinguishable in the quantum-mechanical sense, whereas the condensed gas of pairs may still be regarded as composed of identical entities. The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) condensed phase of moving pairs is by far more robust in the applied field for the case with spin-dependent masses than in the situation with equal masses of quasiparticles. Relative stability of the Bardeen-Cooper-Schrieffer vs FFLO phase is analyzed in detail on temperature-applied field plane. Although our calculations are carried out for a model situation, we can conclude that the spin-dependent masses should play an important role in stabilizing high-field low-temperature unconventional superconducting phases (FFLO, for instance) in systems such as CeCoIn5, organic metals, and possibly others.