中国物理B ›› 2013, Vol. 22 ›› Issue (11): 110309-110309.doi: 10.1088/1674-1056/22/11/110309

• GENERAL • 上一篇    下一篇

Quantum phase transitions of fermionic atoms in an anisotropic triangular optical lattice

保安a, 陈耀桦b, 章晓中a   

  1. a Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
    b Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2013-03-04 修回日期:2013-04-22 出版日期:2013-09-28 发布日期:2013-09-28
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11074141, 11174169, and 10934010), the National Natural Science Foundation of China and Research Grant Council (NSFC/RGC) Joint Research Scheme (Grants No. 11061160490), and the National Basic Research Program of China (Grants Nos. 2011CB921502, 2012CB821305, 2010CB922904, 2009CB930701, and 2009CB929202).

Quantum phase transitions of fermionic atoms in an anisotropic triangular optical lattice

Bao An (保安)a, Chen Yao-Hua (陈耀桦)b, Zhang Xiao-Zhong (章晓中)a   

  1. a Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
    b Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2013-03-04 Revised:2013-04-22 Online:2013-09-28 Published:2013-09-28
  • Contact: Bao An E-mail:ba09@mails.tsinghua.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11074141, 11174169, and 10934010), the National Natural Science Foundation of China and Research Grant Council (NSFC/RGC) Joint Research Scheme (Grants No. 11061160490), and the National Basic Research Program of China (Grants Nos. 2011CB921502, 2012CB821305, 2010CB922904, 2009CB930701, and 2009CB929202).

摘要: The effect of anisotropy caused by a confining potential on the properties of fermionic cold atoms in a triangular optical lattice is systematically investigated by using the dynamical cluster approximation combined with the continuous time quantum Monte–Carlo algorithm. The quantum phase diagrams which reflect the temperature–interaction relation and the competition between the anisotropic parameter and the interaction are presented with full consideration of the anisotropy of the system. Our results show that the system undergoes a transition from Fermi liquid to Mott insulator when the repulsive interaction reaches a critical value. The Kondo effect also can be observed in this system and the pseudogap is suppressed at low temperatures due to the Kondo effect. A feasible experiment protocol to observe these phenomena in an anisotropic triangular optical lattice with cold atoms is proposed, in which the hopping terms are closely related to the lattice confining potential and the atomic interaction can be adjusted via the Feshbach resonance.

关键词: triangular optical lattice, cold atoms, cluster dynamical approximation

Abstract: The effect of anisotropy caused by a confining potential on the properties of fermionic cold atoms in a triangular optical lattice is systematically investigated by using the dynamical cluster approximation combined with the continuous time quantum Monte–Carlo algorithm. The quantum phase diagrams which reflect the temperature–interaction relation and the competition between the anisotropic parameter and the interaction are presented with full consideration of the anisotropy of the system. Our results show that the system undergoes a transition from Fermi liquid to Mott insulator when the repulsive interaction reaches a critical value. The Kondo effect also can be observed in this system and the pseudogap is suppressed at low temperatures due to the Kondo effect. A feasible experiment protocol to observe these phenomena in an anisotropic triangular optical lattice with cold atoms is proposed, in which the hopping terms are closely related to the lattice confining potential and the atomic interaction can be adjusted via the Feshbach resonance.

Key words: triangular optical lattice, cold atoms, cluster dynamical approximation

中图分类号:  (Degenerate Fermi gases)

  • 03.75.Ss
37.10.Jk (Atoms in optical lattices) 32.80.Hd (Auger effect) 67.85.Lm (Degenerate Fermi gases)