Charge-Fluctuation-Induced Superconducting State in Two-Dimensional Quarter-Filled Electron Systems

• Kobayashi Akito

  Department of Physics, Nagoya University

• Tanaka Yasuhiro

  Department of Physics, University of Tokyo

• Ogata Masao

  Department of Physics, University of Tokyo

• Suzumura Yoshikazu

  Department of Physics, University of Tokyo

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\\gtrsimV) and charge density wave (CDW) phase (V\\gtrsimU). The CDW-SC and SC-metal phase boundaries exhibit reentrant structures on the V–T (temperature) plane.

Journal

• Journal of the Physical Society of Japan

  Journal of the Physical Society of Japan 73 (5), 1115-1118, 2004

  THE PHYSICAL SOCIETY OF JAPAN

Keywords

• d-wave superconductivity
• spin fluctuation
• charge fluctuation
• nearest-neighbor repulsive interaction
• extended Hubbard model

Details

• CRID: 1390282679163109504
• NII Article ID: 110001954818
• NII Article ID: 210000104785
• NII Article ID: 130004538790
• NII Book ID: AA00704814
• DOI: 10.1143/jpsj.73.1115
• BIBCODE: 2004JPSJ...73.1115K
• ISSN: 13474073
• ISSN: 00319015
• NDL BIB ID: 6940639
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6940639
• Web Site: http://journals.jps.jp/doi/pdf/10.1143/JPSJ.73.1115
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed