Orbital magnetic field driven metal–insulator transition in spinless extended Falicov–Kimball model on a triangular lattice

Abstract

Ground state properties of spinless, extended Falicov-Kimball model (FKM) on a finite size triangular lattice with orbital magnetic field normal to the lattice are studied using numerical diagonalization and Monte-Carlo simulation methods. We show that the ground state configurations of localized electrons strongly depend on the magnetic field. Magnetic field induces a metal to insulator transition accompanied by segregated phase to an ordered regular phase except at density n f = 1/2 of localized electrons. It is proposed that magnetic field can be used as a new tool to produce segregated phase which was otherwise accessible only either with correlated hopping or with large on-site interactions.

Metal-Insulator Transition and Band Magnetism in the Spin-$1/2$ Falicov-Kimball Model on A Triangular Lattice with External Magnetic Field

“…9(b)). With increase in g, first a mixture of segregated phase and regular phase (where up and down f −electrons are distributed on the lattice in a regular fashion [11,23]) (Fig. 9(c)) and after that a complete regular phase for large Variation of ∆/t with g at various values of α is shown in Fig.…”

“…There are some results available for spinless FKM with finite orbital magnetic field [33,34,7]. Effects of orbital magnetic field (normal to the lattice) on the ground state properties of spinless FKM on a triangular lattice with finite electron correlations are already reported [11]. It was found that the magnetic field strongly affects the ground state configurations of localized electrons.…”

“…Further in the above phenomenon electron correlations are ignored. It is well known that electron correlations play an important role in governing the properties of systems in low dimensions [11]. In the presence of electron correlations very few results are known due to complexity of the problem.…”

“…It is shown that these systems may very well be described by different variants of the Falicov-Kimball model (FKM) [15,16,23,24,25,26,27,11] on the triangular lattice. The FKM (having two kinds of states namely itinerant states and localized states) was originally introduced to study the metal-insulator transition in the rare-earth and transition-metal compounds [28,29].…”

“…An uniform external magnetic field on a lattice can be setup by appropriately choosing the hopping of itinerant electrons position dependent. It is similar to the Hofstadters approach [3], where one couples the magnetic field to the orbital degree of freedom of electrons via the Peierls substitution [41], by multiplying the hopping amplitude with a phase factor (A charge particle moving under the influence of an external magnetic field is accompanied by a geometric phase known as the Aharonov-Bohm phase [42]) which depends on the field and on the position of electrons within the lattice [5,11,43].…”