Fate of quasiparticle at Mott transition and interplay with Lifshitz transition studied by correlator projection method

Kota Hanasaki, Masatoshi Imada

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9 Citations (Scopus)

Abstract

Filling-control metal-insulator transition on the two-dimensional Hubbard model is investigated by using the correlator projection method, which takes into account the momentum dependence of the free energy beyond the dynamical mean-field theory. The phase diagram of metals and Mott insulators is analyzed. Lifshitz transitions occur simultaneously with metal-insulator transitions for large Coulomb repulsion. On the other hand, they are separated each other for smaller Coulomb repulsion, where the phase sandwiched by the Lifshitz and metal-insulator transitions appears to show violation of the Luttinger sum rule. Through the metal-insulator transition, quasiparticles retain nonzero renormalization factor and finite quasi-particle weight on both sides of the transition. This supports that the metal-insulator transition is caused not by the vanishing renormalization factor but by the relative shift of the Fermi level into the Mott gap away from the quasiparticle band, in sharp contrast with the original dynamical mean-field theory. Charge compressibility diverges at the critical end point of the first-order Lifshitz transition at finite temperatures. The origin of the divergence is ascribed to the singular momentum dependence of the quasiparticle dispersion.

Original languageEnglish
Article number084702
Journaljournal of the physical society of japan
Volume75
Issue number8
DOIs
Publication statusPublished - 2006 Aug 1

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Keywords

  • Compressibility divergence
  • Filling control
  • Hubbard model
  • Lifshitz transition
  • Metal-insulator transition
  • Quasiparticle dispersion

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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