We present a program for solving exactly the general pairing Hamiltonian based on diagonalization. The generates seniority-zero shell-model-like basis vectors via ‘01’ inversion algorithm. matrix is constructed in this space. evaluates all non-zero elements of “on fly” using scattering operator and search diagonalized by iterative Lanczos OpenMP parallel thus developed, PairDiag, can efficientl...

The level of current understanding of the physics of time-dependent strongly correlated quantum systems is far from complete, principally due to the lack of effective controlled approaches. Recently, there has been progress in the development of approaches for one-dimensional systems. We describe recent developments in the construction of numerical schemes for general (one-dimensional) Hamilton...

A new, recursive method of calculating matrix elements of polynomial hamiltonians is proposed. It is particularly suitable for the recent algebraic studies of the supersymmetric Yang-Mills quantum mechanics in any dimensions. For the D = 2 system with the SU(2) gauge group, considered here, the technique gives exact, closed expressions for arbitrary matrix elements of the hamiltonian and of the...

The magnetization process of the S = 1 and 1/2 kagomé Heisenberg antiferromagnet is studied by means of the numerical exact diagonalization method. It is found that the magnetization curve at zero temperature has a plateau at 1/3 of the full magnetization. In the presence of √ 3 × √ 3 lattice distortion, this plateau is enhanced and eventually the ferrimagnetic state is realized. There also app...

We investigate a pair entanglement of electrons in diatomic molecule, modeled as a correlated double quantum dot attached to the leads. The low-temperature properties are derived from the ground state obtained by utilizing the Rejec-Ramšak variational technique within the framework of EDABI method, which combines exact diagonalization with ab initio calculations. The results show, that single-p...

We discuss the spectral, transport and magnetic properties of quantum nanowires composed of N 6 13 atoms and containing either even or odd numbers of valence electrons. In our approach we combine Exact Diagonalization and Ab Initio calculations (EDABI method). The analysis is performed as a function of the interatomic distance. The momentum distribution differs drastically for those obtained fo...