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

In this paper, we investigate the theory of dynamical axion string emergingfrom chiral symmetry breaking in three-dimensional Weyl semimetals. The chiralsymmetry is spontaneously broken by a charge density wave (CDW) order whichopens an energy gap and converts the Weyl semimetal into an axion insulator.Indeed, the phase fluctuations of the CDW order parameter act as a dynamicalaxion field $\theta({\vec{x}},t)$ and couples to electromagnetic field via$\mathcal{L}_{\theta}=\frac{\theta(\vec{x},t)}{32\pi^2}\epsilon^{\sigma\tau\nu\mu} F_{\sigma\tau} F_{\nu\mu}.$ Additionally, when theaxion insulator is coupled to the background geometry/strain fields viatorsional defects, i.e., screw dislocations, there is a novel interplay betweenthe crystal dislocations and dynamical axion strings (i.e., vortices of the CDWorder parameter). For example, the screw dislocation traps axial charge, andthere is a Berry phase accumulation when an axion string is braided with ascrew dislocation. In addition, a cubic coupling between the axial current andthe geometry fields is non-vanishing and indicates a Berry phase accumulationduring a particular three-loop braiding procedure where a dislocation loop isbraided with another dislocation and they are both threaded by an axion string.We also observe a chiral magnetic effect induced by a screw dislocation densityin the absence of chemical potential imbalance between Weyl points and describean additional chiral geometric effect and a geometric Witten effect.

Response Properties of Axion Insulators and Weyl Semimetals Driven by Screw Dislocations and Dynamical Axion Strings