A Method for the Analysis of Many-Electron Wave Functions

弘之 森

Introducing an auxiliary field to describe strongly correlated electrons, we investigate variational states of the infinite-U Hubbard model in two dimensions. A mean-field analysis shows that the energetically favored electron-decomposition schemes are the slave-boson method and a slave-semion method, in the latter of which an electron is treated as a composite of two kinds of semions. Along each scheme we derive variational singlet wave functions. Variational Monte Carlo calculation shows that the projected Fermi sea is the lowest-energy state among the obtained variational wave functions.

Raymond Constanciel

A theorem is proved which gives the necessary and sufficient conditions on the $p$-particle reduced-density operator restricted to a functional subspace that ensures the separability of the wave function of a fermion system. This theorem is the theoretical basis of a general method of analyzing atomic and molecular wave functions, a method which is able to reveal the existence of somehow chemically discernible subsystems of electrons.

Louis C. Green

Józef Spałek, Adam Rycerz, W. Wójcik

We apply our new method of approach to electronic states in correlated systems [for a brief review, Part I, see: Acta Phys. Pol. B31, 2879 (2000)] to the analysis of the states and electron localization in nanoscopic chains containing up to N = 12 atoms. The Mott and the Hubbard criteria of localization are explicitly evaluated and the importance of the former is stressed. We also define the many-particle wave function and calculate it explicitly for the hydrogen molecule. Further applications of our method are listed at the end.

Cyrus J. Umrigar, Kenneth Geddes Wilson, John W. Wilkins