Ground State, Magnetization Process and Bipartite Quantum Entanglement of a Spin-1/2 Ising-Heisenberg Model on Planar Lattices of Interconnected Trigonal Bipyramids

TL;DR

This paper analyzes the ground state, magnetization, and bipartite quantum entanglement in a spin-1/2 Ising-Heisenberg model on planar lattices with bipyramidal structures, revealing complex phases and entanglement behaviors.

Contribution

It introduces an exact analytical approach combined with Monte Carlo simulations to characterize diverse quantum phases and entanglement properties in a novel lattice model.

Findings

Six distinct ground-state phases identified.

Seven magnetization scenarios with fractional plateaus.

Quantum entanglement strength varies with degeneracy and magnetic field.

Abstract

The ground state, magnetization scenario and the local bipartite quantum entanglement of a mixed spin-$1/2$ Ising--Heisenberg model in a magnetic field on planar lattices formed by identical corner-sharing bipyramidal plaquettes is examined by combining the exact analytical concept of generalized decoration-iteration mapping transformations with Monte Carlo simulations utilizing the Metropolis algorithm. The ground-state phase diagram of the model involves six different phases, namely, the standard ferrimagnetic phase, fully saturated phase, two unique quantum ferrimagnetic phases, and two macroscopically degenerate quantum ferrimagnetic phases with two chiral degrees of freedom of the Heisenberg triangular clusters. The diversity of ground-state spin arrangement is manifested themselves in seven different magnetization scenarios with one, two or three fractional plateaus whose values are determined by the number of corner-sharing plaquettes. The low-temperature values of the concurrence demonstrate that the bipartite quantum entanglement of the Heisenberg spins in quantum ferrimagnetic phases is field independent, but twice as strong if the Heisenberg spin arrangement is unique as it is two-fold degenerate.