Dynamical Effective Medium Theory for Quantum Spins and Multipoles

Yoshio Kuramoto, Noboru Fukushima

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


A dynamical effective medium theory is presented for quantum spins and higher multipoles such as quadrupole moments. The theory is a generalization of the spherical model approximation for the Ising model, and is accurate up to O(1/zn) where zn is the number of interacting neighbors. The polarization function is optimized under the condition that it be diagonal in site indices. With use of auxiliary fields and path integrals, the theory is flexibly applied to quantum spins and higher multipoles with many interacting neighbors. A Kondo-type screening of each spin is proposed for systems with extreme quantum fluctuations but without conduction electrons.

Original languageEnglish
Pages (from-to)583-593
Number of pages11
Journaljournal of the physical society of japan
Issue number2
Publication statusPublished - 1998 Feb
Externally publishedYes


  • CeB
  • Dynamical effective medium
  • Heisenberg model
  • Ising model
  • Large dimensions
  • Quadrupole moment
  • Quantum fluctuation
  • Spherical model
  • TmTe

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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