#### New Search

##### Export article

Other versions available

### Magnetization dynamics fingerprints of an excitonic condensate $t2g4$ magnet

Jacek Herbrych, Gonzalo Alvarez, Elbio Dagotto
Published: 20 December 2021

Abstract: The competition between spin-orbit coupling (SOC) $\lambda$ and electron-electron interaction $U$ leads to a plethora of novel states of matter, extensively studied in the context of ${t}_{2g}^{4}$ and ${t}_{2g}^{5}$ materials, such as ruthenates and iridates. Excitonic magnets—the antiferromagnetic state of bounded electron-hole pairs-are prominent examples of phenomena driven by those competing energy scales. Interestingly, recent theoretical studies predicted that excitonic magnets can be found in the ground state of SOC ${t}_{2g}^{4}$ Hubbard models. Here we present a detailed computational study of the magnetic excitations in that excitonic magnet, employing one-dimensional chains (via density matrix renormalization group) and small two-dimensional clusters (via Lanczos). Specifically, first we show that the 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 a high-energy optical mode with the highest intensity at wave-vector $q\to 0$. In the excitonic condensation regime at large $U$, we also have found a novel high-energy $\pi$ mode composed solely of orbital excitations. These features do not appear all together in any of the neighboring states in the phase diagram and thus constitute unique fingerprints of the ${t}_{2g}^{4}$ excitonic magnet, of importance in the analysis of neutron and resonant inelastic x-ray scattering experiments.
Keywords: http / www.w3.org/1998/Math/MathML / msubsup / mrow / math xmlns / condensation

#### Scifeed alert for new publications

Never miss any articles matching your research from any publisher
• Get alerts for new papers matching your research
• Find out the new papers from selected authors
• Updated daily for 49'000+ journals and 6000+ publishers
• Define your Scifeed now

#### Share this article

Click here to see the statistics on "Physical Review B" .
##### Cited by 2 articles
Back to Top Top