Supersolid phase and magnetization plateaus observed in anisotropic spin-3/2 Heisenberg model on bipartite lattices

TL;DR

This study investigates the anisotropic spin-3/2 Heisenberg model on bipartite lattices, revealing magnetization plateaus, superfluid, and supersolid phases, with potential experimental relevance to layered magnetic materials.

Contribution

It introduces a comprehensive analysis combining variational, DMRG, and exact diagonalization methods to explore phase diagrams and emergent phases in the model.

Findings

Magnetization plateaus with translational and two-sublattice order identified.

Superfluid and supersolid phases emerge between plateaus for small finite J.

Model may explain anomalies in magnetization curves of layered compounds.

Abstract

We study the spin-3/2 Heisenberg model including easy-plane and exchange anisotropies in one and two dimensions. In the Ising limit, when the off-diagonal exchange interaction J is zero, the phase diagram in magnetic field is characterized by magnetization plateaus that are either translationally invariant or have a two-sublattice order, with phase boundaries that are macroscopically degenerate. Using a site factorized variational wave function and perturbational expansion around the Ising limit, we find that superfluid and supersolid phases emerge between the plateaus for small finite values of J. The variational approach is complemented by a Density Matrix Renormalization Group study of a one-dimensional chain and exact diagonalization calculations on small clusters of a square lattice. The studied model may serve as a minimal model for the layered Ba2CoGe2O7 material compound, and we believe that the vicinity of the uniform 1/3 plateau in the model parameter space can be observed as an anomaly in the measured magnetization curve.