Saved in:
Bibliographic Details
Main Authors: Wang, Si-Cheng, Liu, Zheng-Xin
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.20772
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908750445543424
author Wang, Si-Cheng
Liu, Zheng-Xin
author_facet Wang, Si-Cheng
Liu, Zheng-Xin
contents A spin supersolid is characterized by the simultaneous breaking of lattice translation and continuous spin rotation symmetries. In this work, we study a spin-1 model with $U(2)\cong SU(2)\times U(1)/Z_2$ symmetry on the triangular lattice, and the phase diagram is figured out using a variational $\mathbb CP^2$ approach. We identify a novel $SU(2)$-supersolid phase which contains a 3-sublattice solid order and a spin-superfluid order. Unlike usual supersolid phases having noncollinear magnetic order and only one Goldstone mode, the $SU(2)$-supersolid phase has collinear Neel order and two Goldstone modes. Another important feature of this supersolid is that the magnon excitation spectrum has symmetry protected double degeneracy in the whole Brillouin zone. As by-products, several other ordered phases are obtained, including the ferromagnetic and the antiferromagnetic states breaking the $SU(2)$ symmetry, as well as genuine phases that completely break the $U(2)$ symmetry. Furthermore, the instabilities of $SU(3)$-flavor linear spin-wave theory are consistent with the phase boundaries between different ordered phases. %dispersions confirm the stability of the classically ordered phases and provides insights into their excitation spectra.
format Preprint
id arxiv_https___arxiv_org_abs_2509_20772
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Super-Solid phase in a U(2) symmetric S = 1 Magnet on the Triangular Lattice
Wang, Si-Cheng
Liu, Zheng-Xin
Strongly Correlated Electrons
A spin supersolid is characterized by the simultaneous breaking of lattice translation and continuous spin rotation symmetries. In this work, we study a spin-1 model with $U(2)\cong SU(2)\times U(1)/Z_2$ symmetry on the triangular lattice, and the phase diagram is figured out using a variational $\mathbb CP^2$ approach. We identify a novel $SU(2)$-supersolid phase which contains a 3-sublattice solid order and a spin-superfluid order. Unlike usual supersolid phases having noncollinear magnetic order and only one Goldstone mode, the $SU(2)$-supersolid phase has collinear Neel order and two Goldstone modes. Another important feature of this supersolid is that the magnon excitation spectrum has symmetry protected double degeneracy in the whole Brillouin zone. As by-products, several other ordered phases are obtained, including the ferromagnetic and the antiferromagnetic states breaking the $SU(2)$ symmetry, as well as genuine phases that completely break the $U(2)$ symmetry. Furthermore, the instabilities of $SU(3)$-flavor linear spin-wave theory are consistent with the phase boundaries between different ordered phases. %dispersions confirm the stability of the classically ordered phases and provides insights into their excitation spectra.
title Super-Solid phase in a U(2) symmetric S = 1 Magnet on the Triangular Lattice
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2509.20772