Electronic and magnetic correlations in quantum entanglement of 1D Extended Hubbard Model

Abstract

The Hubbard model is one of the basic models in condensed matter physics. It provides a simple way to understand how electron interactions can generate very rich phase diagrams. This paper aims to study its electronic, magnetic and quantum aspects. The considered Extended Hubbard Model (EHM) is parameterized by kinetic energy t, on-ste interaction energy U, off-ste interaction energy V and exchange spin–spin interaction J.The diagonalization of the t-U-V- model allows us to study the effect of V on some local properties of the half-filled chain fermions. The behaviour of ground state energy as a function of U and V shows that this model exhibits a conductor – insulator transition near the line U=2V. While, the diagonalization of the t-U-V-J- model shows that spin–spin interaction generates a Spin Density Wave (SDW) and Charge Density Wave (CDW) separation. Moreover, to study the quantum aspect of the t-U-V-J- model, we analyse the behaviour of its quantum entanglement. The obtained results show that the quantum entanglement reach its maximum value for an optimal inter-atomic distance.