Numerical Study of Spin-1/2 XXZ Model on Square Lattice from Tensor Product States

TL;DR

This paper uses tensor product states to numerically analyze the spin-1/2 XXZ model on a square lattice, revealing a first-order transition and matching quantum Monte Carlo results, demonstrating the method's effectiveness.

Contribution

It introduces a tensor product states algorithm to study quantum phase transitions, showing its accuracy in capturing first-order transitions in two-dimensional systems.

Findings

Identification of a first-order spin-flip transition at large anisotropy.

Quantitative agreement of critical field with quantum Monte Carlo data.

Demonstration of the method's efficiency in studying 2D quantum phase transitions.

Abstract

By means of the recently proposed algorithm based on the tensor product states, the magnetization process of the spin-1/2 anti-ferromagnetic XXZ model on a square lattice is investigated. In the large spin-anisotropy limit, clear evidence of a first-order spin-flip transition is observed as an external magnetic field is increased. Our findings of the critical field and the discrete jumps in various local order parameters are in good agreement with the quantum Monte Carlo data in the literature. Our results imply that this algorithm can be an accurate and efficient numerical approach in studying first-order quantum phase transitions in two dimensions.