The exact ground state of four electrons in an arbitrary large two-leg Hubbard ladder is deduced from nine analytic and explicit linear equations. The procedure used is described, and the properties of the ground state are analyzed. The method is based on the construction in r-space of the different type of orthogonal basis wave vectors which span the subspace of the Hubert space containing the ground state. In order to do this, we start from the possible microconrigurations of the four particles within the system. These microconrigurations are then rotated, translated and spin-reversed in order to build up the basis vectors of the problem. A closed system of nine analytic linear equations is obtained whose secular equation, by its minimum energy solution, provides the ground-state energy and the ground-state wave function of the model.
ASJC Scopus subject areas
- Condensed Matter Physics