Study of Superconducting Transition Temperature in d–p Model on Basis of Perturbation Theory

• Shinkai Shogo

  Depertment of Physics, Kyoto University

• Ikeda Hiroaki

  Depertment of Physics, Kyoto University

• Yamada Kosaku

  Depertment of Physics, Kyoto University

抄録

We investigate the mass enhancement factor and the superconducting transition temperature T_c in the d–p model, to explain differences of T_c observed in the high-T_c cuprates, such as YBa₂Cu₃O_7−δ (YBCO) and La_2−xSr_xCuO₄ (LSCO). First, we calculate the mass enhancement factor by expanding the normal selfenergy perturbatively up to the fourth order with respect to the on-site repulsion U. The large mass enhancement is obtained when the energy level splitting between the d-level and the p-level is large, which corresponds to LSCO. Next, we calculate T_c by expanding the effective pairing interaction up to the third order and solving the Éliashberg equation in the renormalized quasiparticle scheme. As results, T_c is remarkably suppressed due to the large mass renormalization factor when the level splitting is large. We conclude that the strong correlation in LSCO enhances the pairing interaction but reduces the quasiparticle energy scale more efficiently, and then T_c in LSCO is lower than that in YBCO.

収録刊行物

• Ｊｏｕｒｎａｌ　ｏｆ　ｔｈｅ　Ｐｈｙｓｉｃａｌ　Ｓｏｃｉｅｔｙ　ｏｆ　Ｊａｐａｎ

  Ｊｏｕｒｎａｌ　ｏｆ　ｔｈｅ　Ｐｈｙｓｉｃａｌ　Ｓｏｃｉｅｔｙ　ｏｆ　Ｊａｐａｎ 75 (10), 104712-, 2006

  一般社団法人 日本物理学会

キーワード

• mass enhancement
• d–p model
• high-<I>T</I><SUB>c</SUB> cuprate
• fourth order
• perturbation
• selfenergy

詳細情報

• CRID: 1390001204190068736
• NII論文ID: 110004821525
• NII論文ID: 210000106374
• NII書誌ID: AA00704814
• DOI: 10.1143/jpsj.75.104712
• BIBCODE: 2006JPSJ...75j4712S
• ISSN: 13474073
• ISSN: 00319015
• NDL書誌ID: 8085427
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8085427
• Web Site: http://journals.jps.jp/doi/pdf/10.1143/JPSJ.75.104712
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可