Frustration induced noncollinear magnetic order phase in one-dimensional Heisenberg chain with alternating antiferromagnetic and ferromagnetic next nearest neighbor interactions

TL;DR

This paper investigates the quantum phase transitions and magnetic order in a one-dimensional Heisenberg chain with alternating antiferromagnetic and ferromagnetic interactions, revealing a frustration-induced noncollinear magnetic phase.

Contribution

It introduces a detailed analysis of quantum phase transitions in a frustrated Heisenberg chain using multiple numerical methods, highlighting the emergence of a noncollinear magnetic phase due to frustration.

Findings

Existence of a critical frustration parameter ac1 for phase transition

Transition changes from second-order classically to first-order quantum

Absence of a finite critical point ac2 in the thermodynamic limit

Abstract

By using the coupled cluster method, the numerical exact diagonalization method, and the numerical density matrix renormalization group method, we investigated the properties of the one-dimensional Heisenberg chain with alternating antiferromagnetic and ferromagnetic next nearest neighbor interactions. In the classical limit, the ground state is in the collinear Neel state if a<1/2, while for a>1/2, there is an noncollinear canted state. For the quantum case, we found that, although the classical Neel state is absent, the canted state exists if the frustration parameter a exceeds a critical point ac1. The precise critical point ac1 can be determined by using the coupled cluster method and the numerical exact diagonalization method separately. The results of the coupled cluster method and the exact diagonalization method both disclose that the type of phase transition occurring at ac1 changes from a classical second-order transition to a quantum first-order transition due to quantum fluctuation. Although there is another critical point ac2 in a finite system at which the ground state evolves from the canted state to the collinear Neel plus ferromagnetic state, that state is absent because ac2 tends to infinity in the thermodynamic limit.