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 apply time-dependent density functional theory to calculate the transversemagnetic susceptibility of bcc-Cr and Cr$_2$O$_3$, which constituteprototypical examples of antiferromagnets with itinerant and localized magneticmoments respectively. The exchange-correlation kernel is rescaled in order toenforce the Goldstone condition and the magnon dispersion relations areextracted based on a symmetry analysis relying on the generalized Onsagerrelation. Doing so, our calculations yield the characteristic linear magnondispersion of antiferromagnets in the long wavelength limit. In the case ofCr$_2$O$_3$, we find that the adiabatic local density approximation yields agood qualitative agreement with the measured dispersion, but overestimates themagnon velocity and bandwidth by a factor of two. Including a Hubbardcorrection improves the magnon velocity, but at the expense of the overallqualitative agreement with the experimental magnon dispersion. For bcc-Cr wefind a sharp acoustic magnon mode at low energies with a velocity in agreementwith previously reported values. At higher energies, the acoustic magnon modebecomes subject to strong Landau damping and rapidly vanishes once it entersthe Stoner continuum. In addition to the acoustic magnon mode, we also observean additional collective mode along the $\Gamma\rightarrow\mathrm{R}$ directionwith an energy of $\sim$ 1 eV, which is located inside the Stoner continuum,but appears to elude the effect of Landau damping.

Magnons in antiferromagnetic bcc-Cr and Cr$_2$O$_3$ from time-dependent density functional theory