Numerical study of low-energy states in strongly-correlated electron models

Nobuhiro Sue, Yuhei Natsume, 須江 信洋 +1 more

Hiroyuki Shiba, Masao Ogata

Andreas Giesekus, U. Brandt

We study a class of exactly solvable models for strongly correlated electrons, defined on a set of N cells, and with infinite on-site repulsion on part of the sites of each cell. For 2N or more electrons the exact ground state is known. We construct a tractable (2N-1)-particle state which becomes asymptotically degenerate to the ground state in the thermodynamic limit for one special D-dimensional model. For other models, that state may be used to calculate variational upper bounds on the ground-state energy. For a Hubbard chain with three sites per unit cell, the analytical bound is compared to numerically exact results. \textcopyright{} 1996 The American Physical Society.

Qing Feng Zhong

Hiroyuki Shiba, Masao Ogata

There are two fundamental models for one-dimensional strongly correlated electrons: the Hubbard model and the t-J model. Recent intensive efforts have led to clarifying many important aspects of those systems, whose low-energy behaviors can be described as Luttinger liquid. This paper reviews current status of our understanding, which has been achieved with analytic and numerical approaches.

Tôru Sakai