Valence-band satellite in ferromagnetic nickel: LDA+DMFT study with exact diagonalization

Polarons in the three-band Peierls-Hubbard model: An exact diagonalization study.

We have studied the three-band Peierls-Hubbard model describing the Cu-O layers in high-T c superconductors by using Lanczos diagonalization and assuming infinite mass for the ions. When the system is doped with one hole, and for λ (the electron-lattice coupling strength) greater than a critical value, we found that the oxygens around one Cu contract and the hole self-traps forming a lattice an...

An exact-diagonalization study of rare events in disordered conductors

We determine the statistical properties of wave functions in disordered quantum systems by exact diagonalization of one-, twoand quasi-one dimensional tight-binding Hamiltonians. In the quasi-one dimensional case we find that the tails of the distribution of wave-function amplitudes are described by the non-linear σ-model. In two dimensions, the tails of the distribution function are consistent...

Spin dynamics in a double quantum dot: Exact diagonalization study

Exact-diagonalization study of the one-dimensional disordered XXZ model.

We investigate the one-dimensional quantum XXZ model in the presence of diagonal disorder. Recently the model has been analyzed with the help of field-theoretical renormalization group methods, and a phase diagram has been predicted. We study the model with exact diagonalization techniques up to chain lengths of 16 sites. Using finite-size scaling methods we estimate critical exponents and the ...

Accelerated convergence in exact-diagonalization studies.

A simple method is proposed and tested for obtaining accelerated convergence of quantum systems on small lattices with N sites. The main idea is to perform exact diagonalizations with some added irrelevant parameter, and use this parameter to accelerate the convergence to the infinitelattice limit. In this paper di8'erent boundary conditions are used to improve the convergence for the Heisenber...