On the ground-state degeneracy and entropy in a double-tetrahedral chain formed by the localized Ising spins and mobile electrons

Abstract

Ground-state properties of a hybrid double-tetrahedral chain, in which the localized Ising spins regularly alternate with triangular plaquettes occupied by a variable number of mobile electrons, are exactly investigated. We demonstrate that the zero-temperature phase diagram of the model involves several non-degenerate, two-fold degenerate and macroscopically degenerate chiral phases. Low-temperature dependencies of the entropy and specific heat are also examined in order to gain a deeper insight into the degeneracy of individual ground-state phases and phase transitions. It is shown that a diversity of the ground-state degeneracy manifests itself in multiple-peak structures of both thermodynamic quantities. A remarkable temperature dependencies of the specific heat with two and three Schottky-type maxima are discussed in detail.

8 pages, 6 figures, contribution to SCES2017 conference

References in corpus (4)

• Vigorous thermal excitations in a double-tetrahedral chain of localized Ising spins and mobile electrons mimic a temperature-driven first-order phase transition
• Magnetic Gruneisen parameter and magnetocaloric properties of a coupled spin-electron double-tetrahedral chain
• Ground-state and magnetocaloric properties of a coupled spin-electron double-tetrahedral chain (exact study at the half filling)
• Doping-dependent magnetization plateaus of a coupled spin-electron chain: exact results

Cited by in corpus (3)

• Macroscopic ground-state degeneracy and magnetocaloric effect in the exactly solvable spin-1/2 Ising-Heisenberg double-tetrahedral chain
• Frustrated quantum Heisenberg double-tetrahedral and octahedral chains at high magnetic fields
• Insights into Magnetic Properties of a Mixed Spin-Electron Model on Decorated Planar Lattices Composed of Half-filled Trigonal Bipyramids