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 study the quantum multicritical point in a (2+1)-dimensional Dirac systembetween the semimetallic phase and two ordered phases that are characterized byanticommuting mass terms with $O(N_1)$ and $O(N_2)$ symmetry, respectively.Using $\epsilon$ expansion around the upper critical space-time dimension offour, we demonstrate the existence of a stable renormalization-group fixedpoint, enabling a direct and continuous transition between the two orderedphases directly at the multicritical point. This point is found to becharacterized by an emergent $O(N_1+N_2)$ symmetry for arbitrary values of$N_1$ and $N_2$ and fermion flavor numbers $N_f$, as long as the correspondingrepresentation of the Clifford algebra exists. Small $O(N)$-breakingperturbations near the chiral $O(N)$ fixed point are therefore irrelevant. Thisresult can be traced back to the presence of gapless Dirac degrees of freedomat criticality, and it is in clear contrast to the purely bosonic $O(N)$ fixedpoint, which is stable only when $N < 3$. As a by-product, we obtainpredictions for the critical behavior of the chiral $O(N)$ universality classesfor arbitrary $N$ and fermion flavor number $N_f$. Implications for criticalWeyl and Dirac systems in 3+1 dimensions are also briefly discussed.

Compatible orders and fermion-induced emergent symmetry in Dirac systems