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

Motivated by recent experiments on Bi$_3$Mn$_4$O$_{12}$(NO$_3$), we study afrustrated $J_1$-$J_2$ Heisenberg model on the two dimensional (2D) honeycomblattice. The classical $J_1$-$J_2$ Heisenberg model on the two dimensional (2D)honeycomb lattice has N\'eel order for $J_2 < J_1/6$. For $J_2 > J_1/6$, itexhibits a one-parameter family of degenerate incommensurate spin spiral groundstates where the spiral wave vector can point in any direction. Spin wavefluctuations at leading order lift this accidental degeneracy in favor ofspecific wave vectors, leading to spiral order by disorder. For spin $S=1/2$,quantum fluctuations are, however, likely to be strong enough to melt thespiral order parameter over a wide range of $J_2/J_1$. Over a part of thisrange, we argue that the resulting state is a valence bond solid (VBS) withstaggered dimer order - this VBS is a nematic which breaks lattice rotationalsymmetry. Our arguments are supported by comparing the spin wave energy withthe energy of the dimer solid obtained using a bond operator formalism. Turningto the effect of thermal fluctuations on the spiral ordered state, any nonzerotemperature destroys the magnetic order, but the discrete rotational symmetryof the lattice remains broken resulting in a thermal analogue of the nematicVBS. We present arguments, supported by classical Monte Carlo simulations, thatthis nematic transforms into the high temperature symmetric paramagnet via athermal phase transition which is in the universality class of the classical3-state Potts (clock) model in 2D. We discuss the possible relevance of ourresults for honeycomb magnets, such as Bi$_3$M$_4$O$_{12}$(NO$_3$) (withM=Mn,V,Cr), and bilayer triangular lattice magnets.

Spiral order by disorder and lattice nematic order in a frustrated Heisenberg antiferromagnet on the honeycomb lattice