Charge-fluctuation-induced superconducting state in two-dimensional quarter-filled electron systems

Akito Kobayashi, Yasuhiro Tanaka, Masao Ogata, Yoshikazu Suzumura

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

We investigate superconducting (SC) states in a two-dimensional extended Hubbard model at quarter-filling with on-site repulsive interaction (U) and nearest-neighbor repulsive interaction (V), which lead to spin fluctuation and charge fluctuation, respectively. The effect of charge fluctuation on the onset of the SC state is estimated by calculating pairing interaction within the random phase approximation. Solving a linearized Eliashberg equation with an anomalous self-energy as a function of both momentum and frequency, we examine the stability of a singlet SC state in a phase diagram of U and V with fixed temperatures. We obtain a novel result that the obtained SC state has d xy symmetry in the vicinity of both spin density wave (SDW) phase (U ≳ V) and charge density wave (CDW) phase (V ≳ U). The CDW-SC and SC-metal phase boundaries exhibit reentrant structures on the V-T (temperature) plane.

Original languageEnglish
Pages (from-to)1115-1118
Number of pages4
Journaljournal of the physical society of japan
Volume73
Issue number5
DOIs
Publication statusPublished - 2004 May 1

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Keywords

  • Charge fluctuation
  • Extended Hubbard model
  • Nearest-neighbor repulsive interaction
  • Spin fluctuation
  • d-wave superconductivity

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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