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 investigate the phase diagram of the Heisenberg antiferromagnet on the square lattice with two different nearest-neighbour bonds J and J' (J-J' model) at zero temperature. The model exhibits a quantum phase transition at a critical value J'c ≥J between a semi-classically ordered Neel and a magnetically disordered quantum paramagnetic phase of valence-bond type, which is driven by local singlet formation on J' bonds. We study the influence of spin quantum number s on this phase transition by means of a variational mean-field approach, the coupled cluster method and the Lanczos exact-diagonalization technique. We present evidence that the critical value J'c increases with growing s according to J'c ∝ s(s+1)

Influence of the spin quantum number s on the zero-temperature phase transition in the square-lattice J– model