中国物理B ›› 2008, Vol. 17 ›› Issue (5): 1623-1628.doi: 10.1088/1674-1056/17/5/016
朱 璇, 童培庆
Zhu Xuan(朱璇) and Tong Pei-Qing(童培庆)†
摘要: The half-filled Hubbard chains with the Fibonacci and Harper modulating site potentials are studied in a self-consistent mean-field approximation. A new order parameter is introduced to describe a charge density order. We also calculate the von Neumann entropy of the ground state. The results show that the von Neumann entropy can identify a CDW/SDW (charge density wave/spin density wave) transition for quasiperiodic models.
中图分类号: (Lattice fermion models (Hubbard model, etc.))