中国物理B ›› 2019, Vol. 28 ›› Issue (10): 107102-107102.doi: 10.1088/1674-1056/ab4279

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Hubbard model on an anisotropic checkerboard lattice at finite temperatures: Magnetic and metal-insulator transitions

Hai-Di Liu(刘海迪)   

  1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
  • 收稿日期:2019-06-11 修回日期:2019-08-05 出版日期:2019-10-05 发布日期:2019-10-05
  • 通讯作者: Hai-Di Liu E-mail:hdliu@wipm.ac.cn

Hubbard model on an anisotropic checkerboard lattice at finite temperatures: Magnetic and metal-insulator transitions

Hai-Di Liu(刘海迪)   

  1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
  • Received:2019-06-11 Revised:2019-08-05 Online:2019-10-05 Published:2019-10-05
  • Contact: Hai-Di Liu E-mail:hdliu@wipm.ac.cn

摘要:

We study magnetic and Mott transitions of the Hubbard model on the geometrically frustrated anisotropic checkerboard lattice at half filling using cellular dynamical mean-field theory. Phase diagrams over a wide area of the parameter space are obtained by varying the interparticle interaction strength, geometric frustration strength, and temperature. Our results show that frustration and thermal fluctuations play a competing role against the interactions and in general favor a metallic phase without antiferromagnetic order. Due to their interplay, the system exhibits competition between antiferromagnetic insulator, antiferromagnetic metal, paramagnetic insulator, and paramagnetic metal phases in the intermediate-interaction regime. In the strong-interaction limit, which reduces to the Heisenberg model, our result is consistent with previous studies.

关键词: geometrical frustration, checkerboard lattice, Hubbard model

Abstract:

We study magnetic and Mott transitions of the Hubbard model on the geometrically frustrated anisotropic checkerboard lattice at half filling using cellular dynamical mean-field theory. Phase diagrams over a wide area of the parameter space are obtained by varying the interparticle interaction strength, geometric frustration strength, and temperature. Our results show that frustration and thermal fluctuations play a competing role against the interactions and in general favor a metallic phase without antiferromagnetic order. Due to their interplay, the system exhibits competition between antiferromagnetic insulator, antiferromagnetic metal, paramagnetic insulator, and paramagnetic metal phases in the intermediate-interaction regime. In the strong-interaction limit, which reduces to the Heisenberg model, our result is consistent with previous studies.

Key words: geometrical frustration, checkerboard lattice, Hubbard model

中图分类号:  (Theories and models of many-electron systems)

  • 71.10.-w
05.30.Rt (Quantum phase transitions) 71.10.Fd (Lattice fermion models (Hubbard model, etc.))