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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The mixed spin-1/2 and spin-S Ising model on the Union Jack (centered square)lattice with four different three-spin (triplet) interactions and the uniaxialsingle-ion anisotropy is exactly solved by establishing a rigorous mappingequivalence with the corresponding zero-field (symmetric) eight-vertex model ona dual square lattice. A rigorous proof of the aforementioned exact mappingequivalence is provided by two independent approaches exploiting either agraph-theoretical or spin representation of the zero-field eight-vertex model.An influence of the interaction anisotropy as well as the uniaxial single-ionanisotropy on phase transitions and critical phenomena is examined inparticular. It is shown that the considered model exhibits a strong-universalcritical behaviour with constant critical exponents when considering theisotropic model with four equal triplet interactions or the anisotropic modelwith one triplet interaction differing from the other three. The anisotropicmodels with two different triplet interactions, which are pairwise equal toeach other, contrarily exhibit a weak-universal critical behaviour withcritical exponents continuously varying with a relative strength of the tripletinteractions as well as the uniaxial single-ion anisotropy. It is evidencedthat the variations of critical exponents of the mixed-spin Ising models withthe integer-valued spins S differ basically from their counterparts with thehalf-odd-integer spins S.

Strong- and weak-universal critical behaviour of a mixed-spin Ising model with triplet interactions on the Union Jack (centered square) lattice