The ground-state magnetic ordering of the spin-1/2 frustrated J1-J2 XXZ model on the square lattice

TL;DR

This study investigates how exchange anisotropy affects the magnetic phases of the spin-1/2 frustrated J1-J2 XXZ model on a square lattice, revealing the shrinking of the quantum disordered phase with increasing anisotropy.

Contribution

It provides a detailed analysis of the ground-state phase diagram considering exchange anisotropy using coupled-cluster and exact diagonalization methods, highlighting the disappearance of the quantum phase at high anisotropy.

Findings

Quantum disordered phase shrinks with increasing anisotropy.

Quantum phase disappears around Delta~1.9.

Narrow quantum paramagnetic region persists at Delta=0.

Abstract

Using the coupled-cluster method for infinite lattices and the exact diagonalization method for finite lattices, we study the influence of an exchange anisotropy Delta on the ground-state phase diagram of the spin-1/2 frustrated J1-J2 XXZ antiferromagnet on the square lattice. We find that increasing Delta>1 (i.e. an Ising type easy-axis anisotropy) as well as decreasing Delta<1 (i.e. an XY type easy-plane anisotropy) both lead to a monotonic shrinking of the parameter region of the magnetically disordered quantum phase. Finally, at Delta~1.9 this quantum phase disappears, whereas in pure XY limit (Delta=0) there is still a narrow region around J2 =0.5J1 where the quantum paramagnetic ground-state phase exists.