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

Using a modified spin-wave theory which artificially restores zero sublatticemagnetization on finite lattices, we investigate the entanglement properties ofthe N\'eel ordered $J_1 - J_2$ Heisenberg antiferromagnet on the squarelattice. Different kinds of subsystem geometries are studied, eithercorner-free (line, strip) or with sharp corners (square). Contributions fromthe $n_G=2$ Nambu-Goldstone modes give additive logarithmic corrections with aprefactor ${n_G}/{2}$ independent of the R\'enyi index. On the other hand,corners lead to additional (negative) logarithmic corrections with a prefactor$l^{c}_q$ which does depend on both $n_G$ and the R\'enyi index $q$, in goodagreement with scalar field theory predictions. By varying the second neighborcoupling $J_2$ we also explore universality across the N\'eel ordered side ofthe phase diagram of the $J_1 - J_2$ antiferromagnet, from the frustrated side$0<J_2/J_1<1/2$ where the area law term is maximal, to the stronglyferromagnetic regime $-J_2/J_1\gg1$ with a purely logarithmic growth$S_q=\frac{n_G}{2}\ln N$, thus recovering the mean-field limit for a subsystemof $N$ sites. Finally, a universal subleading constant term $\gamma_q^{\rmord}$ is extracted in the case of strip subsystems, and a direct relation isfound (in the large-S limit) with the same constant extracted from free latticesystems. The singular limit of vanishing aspect ratios is also explored, wherewe identify for $\gamma_q^\text{ord}$ a regular part and a singular component,explaining the discrepancy of the linear scaling term for fixed width {\it{vs}}fixed aspect ratio subsystems.

Entanglement entropies of the $J_1 - J_2$ Heisenberg antiferromagnet on the square lattice