arXiv:cond-mat/0106089 · Physical review. B, Condensed matter

Electron localization in a one-dimensional nanoscopic system: A combined exact diagonalization–anab initioapproach

Józef Spałek, Adam Rycerz

Published Oct 8, 2001• 13 citations

Abstract

Exact ground-state properties are presented by combining the diagonalization in the Fock space (and taking all hopping integrals and all two-site interactions) with the ab initio optimization of the Wannier functions. Electrons are essentially localized for the interatomic distance $R\ensuremath{\sim}2.0 \AA{}$ for s-like states, when the quasiparticle mass is divergent. The momentum distribution dispersion is proposed to define the localization order parameter. Dimerization and zero-point energies are also discussed. The method provides convergent results for $N>~8$ atoms.

DOI: 10.1103/physrevb.64.161105

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arXiv:cond-mat/0106089 · Physical review. B, Condensed matter

Electron localization in a one-dimensional nanoscopic system: A combined exact diagonalization–anab initioapproach

Józef Spałek, Adam Rycerz

Published Oct 8, 2001• 13 citations

arXiv HTML PDF

Abstract

R\ensuremath{\sim}2.0 \AA{}

for s-like states, when the quasiparticle mass is divergent. The momentum distribution dispersion is proposed to define the localization order parameter. Dimerization and zero-point energies are also discussed. The method provides convergent results for

N>~8

atoms.

DOI: 10.1103/physrevb.64.161105

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R\ensuremath{\sim}2.0 \AA{}

N>~8

atoms.

N>~8.

During this process the Fermi-Dirac distribution is smeared out, the effective band mass increases by \ensuremath{\sim}50%, and the spin-spin correlation functions reduce to those for a Heisenberg antiferromagnet. Values of microscopic parameters such as the hopping and the kinetic-exchange integrals, as well as the magnitude of both intraatomic and interatomic Coulomb and exchange interactions are calculated. We also determine the values of various local electron-lattice couplings, and show that they are comparable to the kinetic exchange contribution in the strong-correlation limit. The magnitudes of the dimerization and the zero-point motion are also discussed. Our results provide a canonical example of a tractable strongly correlated system with a precise, first-principles description as a function of interatomic distance of a model system involving all hopping integrals, all pair-site interactions, and exact one-band Wannier functions.

\lesssim

_{0}

_{0}

is the Bohr radius) and zero-temperature transition to the localized spin system for larger . Possible further applications of the method are listed at the end.