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

By analytic continuation to real theta of data obtained from numericalsimulation at imaginary theta we study the Haldane conjecture and show that theO(3) non-linear sigma model with a theta term in 2 dimensions becomes masslessat theta=3.10(5). A modified cluster algorithm has been introduced to simulatethe model with imaginary theta. Two different definitions of the topologicalcharge on the lattice have been used; one of them needs renormalization tomatch the continuum operator. Our work also offers a successful test fornumerical methods based on analytic continuation.

Mass gap in the 2D O(3) non-linear sigma model with a theta=pi term