STRONGLY CORRELATED SPIN-PHONON SYSTEMS - A SCENARIO FOR HEAVY FERMIONS

被引:22
作者
IOSELEVICH, AS [1 ]
CAPELLMANN, H [1 ]
机构
[1] RUSSIAN ACAD SCI,LANDAU INST THEORET PHYS,MOSCOW 117940,RUSSIA
来源
PHYSICAL REVIEW B | 1995年 / 51卷 / 17期
关键词
D O I
10.1103/PhysRevB.51.11446
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
A lattice of localized spins, coupled to phonons, is considered. It is shown that in a certain range of coupling constants a nontrivial nonmagnetic ground state of the system can arise, where the spins are screened by the phonons. In this state, groups of an even number of spins form singlet clusters, the spins within each cluster being strongly coupled to each other due to the exchange of phonons. This is a purely quantum phenomenon: average lattice displacements are zero, while amplitudes of zero quantum vibrations within the clusters are enhanced; the effect vanishes in the limit of classical spins. The clusters may, in principle, form either a crystal or quantum liquid. The collective screening of spins by phonons is a nonperturbative effect: it takes place only if the coupling constant exceeds a certain threshold. We have found the ground state exactly for a specific model with a highly symmetric Hamiltonian and discussed corrections to our solution due to variations of the Hamiltonian. The thermodynamics of the system is found. Applications to the physics of heavy-fermion compounds are discussed. © 1995 The American Physical Society.
引用
收藏
页码:11446 / 11462
页数:17
相关论文
共 48 条
  • [1] ALTSHULER SA, 1962, SOV PHYS JETP, V16, P1637
  • [2] LIMITS ON THE ENERGY OF THE ANTIFERROMAGNETIC GROUND STATE
    ANDERSON, PW
    [J]. PHYSICAL REVIEW, 1951, 83 (06): : 1260 - 1260
  • [3] ANOMALOUS LOW-TEMPERATURE THERMAL PROPERTIES OF GLASSES AND SPIN GLASSES
    ANDERSON, PW
    HALPERIN, BI
    VARMA, CM
    [J]. PHILOSOPHICAL MAGAZINE, 1972, 25 (01): : 1 - &
  • [4] BERGMANN K, UNPUB
  • [5] PHONON EFFECTS AT THE METAMAGNETIC TRANSITION IN CERU2SI2
    BRULS, G
    WEBER, D
    LUTHI, B
    FLOUQUET, J
    LEJAY, P
    [J]. PHYSICAL REVIEW B, 1990, 42 (07): : 4329 - 4333
  • [6] STRAIN-ORDER-PARAMETER COUPLING AND PHASE-DIAGRAMS IN SUPERCONDUCTING UPT3
    BRULS, G
    WEBER, D
    WOLF, B
    THALMEIER, P
    LUTHI, B
    DE VISSER, A
    MENOVSKY, A
    [J]. PHYSICAL REVIEW LETTERS, 1990, 65 (18) : 2294 - 2297
  • [7] BUZDIN AI, 1980, SOV PHYS USP, V23, P409
  • [8] SPIN-PHONON COUPLING IN INTERMEDIATE VALENCY - EXACTLY SOLVABLE MODELS
    CAPELLMANN, H
    LIPINSKI, S
    [J]. ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1991, 83 (02): : 199 - 205
  • [9] A MICROSCOPIC MODEL FOR THE COUPLING OF SPIN FLUCTUATIONS AND CHARGE FLUCTUATION IN INTERMEDIATE VALENCY
    CAPELLMANN, H
    LIPINSKI, S
    NEUMANN, KU
    [J]. ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1989, 75 (03): : 323 - 329
  • [10] INTERMEDIATE VALENCY .1. COUPLINGS, HAMILTONIAN, AND ELECTRICAL-RESISTIVITY
    CAPELLMANN, H
    NEUMANN, KU
    [J]. ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1987, 67 (01): : 53 - 61