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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The competition between spin-orbit coupling $\lambda$ and electron-electroninteraction $U$ leads to a plethora of novel states of matter, extensivelystudied in the context of $t_{2g}^4$ and $t_{2g}^5$ materials, such asruthenates and iridates. Excitonic magnets -- the antiferromagnetic state ofbounded electron-hole pairs -- is a prominent example of phenomena driven bythose competing energy scales. Interestingly, recent theoretical studiespredicted that excitonic magnets can be found in the ground-state ofspin-orbit-coupled $t_{2g}^4$ Hubbard models. Here, we present a detailedcomputational study of the magnetic excitations in that excitonic magnet,employing one-dimensional chains (via density matrix renormalization group) andsmall two-dimensional clusters (via Lanczos). Specifically, first we show thatthe low-energy spectrum is dominated by a dispersive (acoustic) magnonic mode,with extra features arising from the $\lambda=0$ state in the phase diagram.Second, and more importantly, we found a novel magnetic excitation forming ahigh-energy optical mode with the highest intensity at wavevector $q\to 0$. Inthe excitonic condensation regime at large $U$, we also have found a novelhigh-energy $\pi$-mode composed solely of orbital excitations. These uniquefingerprints of the $t_{2g}^4$ excitonic magnet are important in the analysisof neutron and RIXS experiments.

Magnetization dynamics fingerprints of an excitonic condensate $t_{2g}^{4}$ magnet