English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We introduce a quantum spin-1/2 model with many-body correlatedHeisenberg-type interactions on the 2D square lattice, designed to host aplaquette valence-bond solid (PVBS) ground state breaking $\mathbb{Z}_4$symmetry. We carry out a detailed quantum Monte Carlo study of the quantumphase transition between the antiferromagnetic (AFM) and PVBS states. We find afirst-order transition, in contrast to previously studied continuous'deconfined' transitions between the AFM and columnar valence-bond solids. Weshow that the coexistence state at the AFM--PVBS transition is unexpectedlyassociated with SO(5) symmetry, which may indicate that the transition isconnected to a deconfined critical point. We also discuss the first-ordertransition in the context of a recent proposal of spinons with fractonproperties in the PVBS state, concluding that the fracton scenario is unlikely.Further, we discover a novel type of eight-fold degenerate VBS phase thatbreaks the remaining $\mathbb{Z}_2$ symmetry of the PVBS phase. The PVBS phasecan then be regarded as an intermediate 'vestigial' phase, and we develop ageneral graph-theoretic approach to describe the two-stage discrete symmetrybreaking. At finite temperature, we observe fluctuation-induced first-ordertransitions, which are hallmarks of vestigial phase transitions. We alsomention possible connections to the SO(5) theory of high-T$_{\rm c}$superconductivity.

Valence-bond solids, vestigial order, and emergent SO(5) symmetry in a two-dimensional quantum magnet