Reentrant phase transitions of a coupled spin-electron model on doubly decorated planar lattices with two or three consecutive critical points

Abstract

The generalized decoration-iteration transformation is adapted for the exact study of a coupled spin-electron model on 2D lattices in which localized Ising spins reside on nodal lattice sites and mobile electrons are delocalized over pairs of decorating sites. The model takes into account a hopping term for mobile electrons, the Ising coupling between mobile electrons and localized spins as well as the Ising coupling between localized spins ($J^{\prime }$). The ground state, spontaneous magnetization and specific heat are examined for both ferromagnetic ($J^{\prime }>0$) as well as antiferromagnetic ($J^{\prime }<0$) interaction between the localized spins. Several kinds of reentrant transitions between the paramagnetic ($P$), antiferromagnetic ($AF$) and ferromagnetic ($F$) phases have been found either with a single critical point, or with two consecutive critical points ($P-AF$/$F-P$) and three successive critical points $AF/F-P-F/AF-P$. Striking thermal variations of the spontaneous magnetization depict a strong reduction due to the interplay between annealed disorder and quantum fluctuations in addition to the aforementioned reentrance. It is shown that the specific heat displays diverse thermal dependencies including finite cusps at the critical temperatures.

15 pages, 20 figures

References in corpus (8)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Observation of a localized flat-band state in a photonic Lieb lattice
• Observation of bound states in Lieb photonic lattices
• Fractional magnetization plateaus and magnetic order in the Shastry Sutherland magnet TmB4
• Vigorous thermal excitations in a double-tetrahedral chain of localized Ising spins and mobile electrons mimic a temperature-driven first-order phase transition
• Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds
• Ground state, magnetization process and magnetocaloric effect of the exactly tractable spin-electron tetrahedral chain
• An introduction to numerical methods in low-dimensional quantum systems

Cited by in corpus (5)

• Hubbard pair cluster in the external fields. Studies of the chemical potential
• Hubbard pair cluster with elastic interactions. Studies of thermal expansion, magnetostriction and electrostriction
• Conventional and rotating magnetoelectric effect of a half-filled spin-electron model on a doubly decorated square lattice
• Comparative Study of a Critical Behavior of a Coupled Spin-Electron Model on a Doubly Decorated Square Lattice in the Canonical and Grand-Canonical Ensemble
• Insights into Magnetic Properties of a Mixed Spin-Electron Model on Decorated Planar Lattices Composed of Half-filled Trigonal Bipyramids