Floquet anomalous Hall effect in ferromagnetic multiorbital tight-binding models

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Optics

Background:

• Investigating the electronic properties of transition metal compounds like Sr2RuO4 is crucial for developing novel electronic devices.
• Understanding the influence of external stimuli, such as polarized light, on material properties is key to controlling quantum phenomena.
• Ferromagnetic materials exhibit unique electromagnetic responses, including the anomalous Hall effect, which can be modulated by light.

Purpose of the Study:

• To analyze the band structures and intrinsic anomalous Hall conductivity (AHC) of a ferromagnetic multiorbital tight-binding model of Sr2RuO4.
• To investigate the impact of monochromatic polarized light on these properties within the framework of Floquet theory.
• To explore the interplay between light polarization, frequency, and material characteristics on AHC.

Main Methods:

• Utilizing Floquet theory to describe the system under periodic driving by polarized light.
• Employing the continued fraction technique to derive the effective Hamiltonian and Green's functions.
• Applying the Kubo formalism for transport calculations to determine the intrinsic AHC.

Main Results:

• Low-frequency polarized light significantly impacts band structures by opening bandgaps, unlike high-frequency light.
• Left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) light exhibit distinct effects on AHC.
• The roles of LCP and RCP light can be interchanged by altering the incident light plane.
• The study also examined the combined effects of disorder and circularly polarized light on intrinsic AHC.

Conclusions:

• Floquet theory provides a robust framework for understanding light-matter interactions in complex materials.
• Tailoring light polarization and frequency offers a pathway to control the electronic transport properties, specifically AHC, in Sr2RuO4.
• The findings have implications for designing light-controllable spintronic devices and understanding quantum phenomena in driven systems.