LaFeAsO as a Self Doped Spin-1 Mott Insulator: Quantum String Liquid State and Superconductivity

• Baskaran Ganapathy

  The Institute of Mathematical Sciences, CIT Campus

抄録

We suggest that LaFeAsO is basically a spin-1 Mott insulator that has become an antiferromagnetically ordered bad metal with reduced sublattice moment, by a self (under) doping of an equal and small density (y<<1) of electron and hole carriers. External doping in LaFeAsO_1−xF_x kills long range antiferromagnetic order and stabilises a liquid of quantum singlet strings (spin-1 Haldane chain). We view this state as two spin-1/2 resonating valence bond (RVB) system, coupled by a weak Hund coupling and bond charge repulsions, leading to an AKLT (Affleck, Kennedy, Lieb, and Tasaki) type spin pairing. A pair of doped holes (electrons) creates an open string and remain at the ends as holon (doublon). Charge ± 2e singlet strings condense to produce high T_c superconductivity. Higher T_c’s are likely in our Mott insulator based scenario, when competing orders are taken care of. As Fe–Fe distance increases from LaFePO to LaFeAsO, we suggest that REFeSb) and REFeBiO (RE: rare earth) and also the chalogenide α-FeTe, if synthesized might be spin-1 Mott insulators, with a prospect for higher superconducting T_c.

収録刊行物

• Ｊｏｕｒｎａｌ　ｏｆ　ｔｈｅ　Ｐｈｙｓｉｃａｌ　Ｓｏｃｉｅｔｙ　ｏｆ　Ｊａｐａｎ

  Ｊｏｕｒｎａｌ　ｏｆ　ｔｈｅ　Ｐｈｙｓｉｃａｌ　Ｓｏｃｉｅｔｙ　ｏｆ　Ｊａｐａｎ 77 (11), 113713-113713, 2008

  一般社団法人 日本物理学会

キーワード

• strongly correlated electron systems
• high <I>T</I><SUB>c</SUB> superconductivity
• layered Fe compound superconductors
• Hubbard model
• resonating valence bond state theory

詳細情報

• CRID: 1390282679174723968
• NII論文ID: 130005436251
• NII論文ID: 110006983735
• NII論文ID: 210000107517
• NII書誌ID: AA00704814
• DOI: 10.1143/jpsj.77.113713
• ISSN: 13474073
• ISSN: 00319015
• NDL書誌ID: 9706229
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I9706229
• Web Site: https://journals.jps.jp/doi/pdf/10.1143/JPSJ.77.113713
• 本文言語コード: en
• データソース種別:
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