Effect of external electric field on the charge density waves in one-dimensional Hubbard superlattices

Abstract

We have studied the ground state of one-dimensional Hubbard superlattice structures with different unit-cell sizes in the presence of an electric field. A self-consistent Hartree-Fock approximation calculation is done in the weak- to intermediate-interaction regime. Studying the charge gap at the Fermi level and the charge density structure factor, we get an idea of how the charge modulation on the superlattice is governed by the competition between the electronic correlation and the external electric field.

Switching effect and the metal–insulator transition in electric field

“…The problem of metal-insulator transition (MIT) in an electric field has received increasing attention in the recent time [1][2][3][4][5][6][7][8][9]. This interest, on the one hand, is caused by investigations of negative differential resistance (NDR) effects in some materials exhibiting electronic switching due to the MIT.…”

“…It is pertinent to remind, however, that a structural transition accompanied by the superstructure formation might be, in principle, electronically induced too [2,6,10,11,17]: in electron systems with screened Coulomb interaction, the insulating state with commensurate charge density waves is analogous to an excitonic insulator (EI) [10,17].…”

Electrocaloric effect in cubic Hubbard nanoclusters

“…This is the usual approach (e.g. 62 , 63 ). However, it should be noted here that for the electric field with the potential changing markedly on the scale of lattice constant, the atomic states which give rise to the Hubbard model could be deformed in comparison with the states without field.…”