Ground State Degeneracy of Interacting Spinless Fermions
Strongly Correlated Electrons
2015-10-14 v2
Abstract
We propose an eigen-operator scheme to study the lattice model of interacting spinless fermions at half filling and show that this model possesses a hidden form of reflection positivity in its Majorana fermion representation. Based on this observation, we prove rigourously that the ground state of this model is either unique or doubly degenerate if the lattice size is even, and is always doubly degenerate if is odd. This proof holds in all dimensions with arbitrary lattice structures.
Keywords
Cite
@article{arxiv.1412.1578,
title = {Ground State Degeneracy of Interacting Spinless Fermions},
author = {Zhong-Chao Wei and Xing-Jie Han and Zhi-Yuan Xie and Tao Xiang},
journal= {arXiv preprint arXiv:1412.1578},
year = {2015}
}