Quantum dynamics in a spin-1/2 square lattice $J_{1}$-$J_{2}$-$δ$ altermagnet

Fuente: arXiv
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Autori principali: Liu, Yang, Shao, Shiqi, He, Saisai, Xie, Z. Y., Mei, Jia-Wei, Luo, Hong-Gang, Zhao, Jize
Natura: Preprint
Pubblicazione: 2024
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author Liu, Yang
Shao, Shiqi
He, Saisai
Xie, Z. Y.
Mei, Jia-Wei
Luo, Hong-Gang
Zhao, Jize
author_facet Liu, Yang
Shao, Shiqi
He, Saisai
Xie, Z. Y.
Mei, Jia-Wei
Luo, Hong-Gang
Zhao, Jize
contents A key feature of the newly discovered altermagnet is that its spin degeneracy is lifted, although it has an antiferromagnetic order and zero net magnetization. In this work, we investigate a frustrated spin-1/2 $J_1$-$J_2$-$δ$ Heisenberg model on the square lattice by the tensor network methodin combination with the linear spin-wave theory, with our focus on both the magnon excitations and longitudinal excitations.For a small $J_2$ and a finite range of $δ$ we demonstrate that such a model hosts an altermagnetic ground state. Its magnon spectrum is split into two branches and the largest splitting occurs at $\left(\pmπ/2, \pmπ/2\right)$ in the Brillouin zone. The magnitudes of splitting in the two magnon modes are equal with respect to the case of $δ=0$. Dynamical spin structure factors show that the low-energy peak in the longitudinal spectral weight around $(π/2, π/2)$ is also split, and thus the relative positions of the magnon modes and longitudinal modes in energy may change in the presence of a finite $δ$. These findings demonstrate that the altermagnets harbor more complex quantum dynamics than the conventional collinear antiferromagnets.
format Preprint
id arxiv_https___arxiv_org_abs_2410_06955
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum dynamics in a spin-1/2 square lattice $J_{1}$-$J_{2}$-$δ$ altermagnet
Liu, Yang
Shao, Shiqi
He, Saisai
Xie, Z. Y.
Mei, Jia-Wei
Luo, Hong-Gang
Zhao, Jize
Strongly Correlated Electrons
A key feature of the newly discovered altermagnet is that its spin degeneracy is lifted, although it has an antiferromagnetic order and zero net magnetization. In this work, we investigate a frustrated spin-1/2 $J_1$-$J_2$-$δ$ Heisenberg model on the square lattice by the tensor network methodin combination with the linear spin-wave theory, with our focus on both the magnon excitations and longitudinal excitations.For a small $J_2$ and a finite range of $δ$ we demonstrate that such a model hosts an altermagnetic ground state. Its magnon spectrum is split into two branches and the largest splitting occurs at $\left(\pmπ/2, \pmπ/2\right)$ in the Brillouin zone. The magnitudes of splitting in the two magnon modes are equal with respect to the case of $δ=0$. Dynamical spin structure factors show that the low-energy peak in the longitudinal spectral weight around $(π/2, π/2)$ is also split, and thus the relative positions of the magnon modes and longitudinal modes in energy may change in the presence of a finite $δ$. These findings demonstrate that the altermagnets harbor more complex quantum dynamics than the conventional collinear antiferromagnets.
title Quantum dynamics in a spin-1/2 square lattice $J_{1}$-$J_{2}$-$δ$ altermagnet
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2410.06955