Gemeinsames TKM-TFP Seminar

  • Datum:

    Montag, 14.00-15.30 Uhr

  • Referent:

    Garst, Mirlin, Rockstuhl, Schmalian, Shnirman

  • Ort:

    10-01

Magnon-phonon coupling in dispersive media

Seminar über Theoretische Festkörperphysik

Vortragender:

Victor Augusto Sant Anna Valderramos Bittencourt

Datum:

13.06.2022 14:00

Ort:

Room 10.01, Bldg. 30.23, Campus South and via Zoom

Zugehörigkeit:

Max Planck Institute for the Science of Light

Gastgeber:

Prof. Dr. Alexander Shnirman

Abstract

The quantized magnetic excitations (magnons) of magnetic dielectrics can couple to microwave and optical photons, making such systems prospect hybrid quantum platforms. Prospect applications of the system includes quantum transduction between optics and microwaves, and generation of non-classical macroscopic magnetization states. Nevertheless, one of the limitations of the system is the weakness of the coupling between magnons and optical photons - a consequence of the weakness of the magneto-optical effects in dielectrics. In this talk, I present the concept of a novel platform for magnon-photon interaction based on a magnetic epsilon-near-zero (ENZ) medium, in which strong coupling can be achieved. In ENZ media, the diagonal components of the permittivity tensor vanish at specific frequencies, yielding an enhancement of non-linear effects and secondary responses, such as magneto-optical effects. After a brief review of magnon-photon interactions in magnetic dielectrics and the state-of-the-art optomagnonic systems, I will present a quantisation scheme that phenomenologically includes dispersion, which is the responsible for the ENZ behaviour. Within this framework, the enhancement of magneto-optical effects in ENZ media implies an enhancement of the magnon-photon coupling, which can surpass both magnon and photon decay rates, thus reaching the strong coupling regime. Finally, I discuss a possible measurement scheme for the strong magnon-photon coupling via the optics power spectrum, which exhibits multiple sidebands characteristic of the strong parametric coupling. The proposal of an ENZ-based magnon-photon platform pushes forward novel designs for magnonic systems, and can be the starting point for developing new magnon-based protocols.