Dominant antiferromagnetism in the Hubbard model on anisotropic triangular lattices

被引:5
作者
Watanabe, Tsutomu [1 ]
Yokoyama, Hisatoshi
Tanaka, Yukio
Inoue, Jun-Ichiro
机构
[1] Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 464, Japan
[2] Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan
关键词
Hubbard model; anisotropic triangular lattice; mott transition;
D O I
10.1016/j.jmmm.2006.10.106
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
With kappa-(BEDT-TTF)(2)X in mind, we study a half-filled-band Hubbard model on an anisotropic triangular lattice, using an optimization variational Monte Carlo method. As a trial function, we use a state having antiferromagnetic (AF) and d-wave singlet gaps simultaneously, and allow for a band renormalization effect in it. It is found that, at a fairy small value of U/t, a first- order conductor-to-AF insulator transition takes place even for remarkably large strength of frustration. In the optimized insulating states, the staggered magnetization is always robust, even for fully frustrated case. Thereby, a regime of robust superconductor as well as of a nonmagnetic insulator vanishes in this wave function. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:648 / 650
页数:3
相关论文
共 19 条
[1]  
Chen Y.-C., COMMUNICATION
[2]   PHASE-DIAGRAMS OF THE 2-DIMENSIONAL HUBBARD AND T-J MODELS BY A VARIATIONAL MONTE-CARLO METHOD [J].
GIAMARCHI, T ;
LHUILLIER, C .
PHYSICAL REVIEW B, 1991, 43 (16) :12943-12951
[3]   Coexistence of dx2-y2 superconductivity and antiferromagnetism in the two-dimensional t-J model and numerical estimation of Gutzwiller factors [J].
Himeda, A ;
Ogata, M .
PHYSICAL REVIEW B, 1999, 60 (14) :R9935-R9938
[4]   Spontaneous deformation of the Fermi surface due to strong correlation in the two-dimensional t-J model [J].
Himeda, A ;
Ogata, M .
PHYSICAL REVIEW LETTERS, 2000, 85 (20) :4345-4348
[5]   Electron correlation, metal-insulator transition and superconductivity in quasi-2D organic systems, (ET)(2)X [J].
Kanoda, K .
PHYSICA C, 1997, 282 :299-302
[6]   CLOSE RELATION BETWEEN LOCALIZED-ELECTRON MAGNETISM AND THE PARAMAGNETIC WAVEFUNCTION OF COMPLETELY ITINERANT ELECTRONS [J].
KAPLAN, TA ;
HORSCH, P ;
FULDE, P .
PHYSICAL REVIEW LETTERS, 1982, 49 (12) :889-892
[7]   Phase diagram of superconductivity on the anisotropic triangular lattice Hubbard model:: An effective model of κ-(BEDT-TTF) salts [J].
Kino, H ;
Kontani, H .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1998, 67 (11) :3691-3694
[8]   Phase diagram of two-dimensional organic conductors: (BEDT-TTF)(2)X [J].
Kino, H ;
Fukuyama, H .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1996, 65 (07) :2158-2169
[9]   Realization of superconductivity at ambient pressure by band-filling control in kappa-(BEDT-TTF)(2)Cu-2(CN)(3) [J].
Komatsu, T ;
Matsukawa, N ;
Inoue, T ;
Saito, G .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1996, 65 (05) :1340-1354
[10]   Spin fluctuation-induced superconductivity in organic compounds [J].
Kondo, H ;
Moriya, T .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1998, 67 (11) :3695-3698