Intersite electron correlations in a Hubbard model on inhomogeneous lattices

TMU International Symposium on "New Quantum Phases Emerging from Novel Crystal Structure"

Takemori, Nayuta^1 ; Koga, Akihisa^1 ; Hafermann, Hartmut^2

Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo

152-8551, Japan^1

Mathematical and Algorithmic Sciences Lab, France Research Center, Huawei Technologies Co. Ltd., Boulogne-Billancourt

92100, France^2

关键词: Hopping integrals;    Interaction strength;    Intersite correlation;    Mott transitions;    Nearest neighbors;    Open boundary condition;    Quantum monte carlo;    Square lattices;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/683/1/012040/pdf
DOI  :  10.1088/1742-6596/683/1/012040

来源: IOP

【 摘 要 】

We study intersite electron correlations in the half-filled Hubbard model on square lattices with periodic and open boundary conditions by means of a real-space dual fermion approach. By calculating renormalization factors, we clarify that nearest-neighbor intersite correlations already significantly reduce the critical interaction. The Mott transition occurs at U/t ∼ 6.4, where U is the interaction strength and t is the hopping integral. This value is consistent with quantum Monte Carlo results. It shows the importance of short-range intersite correlations, which are taken into account in the framework of the real-space dual fermion approach.