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Phonon Magnon

  • Wednesday 3 
  • 14:10
  • - 14:30 
  • 1402 
  • Talk # 3 
  • Session # 2

Coherent and Dissipative Coupling in a Magnetomechanical System

Riccardo Cucini1, Pietro Carrara6, Marta Brioschi1,2, Raffaele Silvani4, Adekunle. O Adeyeye5, Giancarlo Panaccione1, Gianluca Gubbiotti3, Giorgio Rossi1,2

  • 1- CNR-Istituto Officina dei Materiali (IOM), Basovizza (TS), 34149, Italy
  • 2- Dipartimento di Fisica, Università degli Studi di Milano, Milano, 20133, Italy
  • 3- Cnr-Istituto Officina dei Materiali (IOM), Unità di Perugia, 06123 Perugia, Italy
  • 4- Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
  • 5- Department of Physics, Durham University, DH1 3LE Durham, United Kingdom
  • 6- Sorbonne Université, CNRS, Institut des NanoSciences de Paris INSP, 75005 Paris, France

Presenting Author:

  • Riccardo
  • Cucini

cucini@iom.cnr.it

Hybrid elastic and spin waves hold promises for energy-efficient and versatile generation and detection of magnetic signals, with potentially long coherence times. Systems based on the coupling between elastic and magnetic degrees of freedom can boost transduction and sensing capabilities, down to the single-quantum detection and manipulation, or allow novel computation, simulation and storage platforms. In particular, magneto-elastic coupling allows for efficient magnon-phonon hybridization in the few gigahertz and inverse micron range, resulting in so-called magnon-phonon polarons.

The main channel of coupling in hybridized system is the so-called coherent coupling, highlighted by a gap (avoided crossing) in the dispersion relation. Recently, a different coupling mechanism was observed, stemming from correlation in the dissipation of the parent modes into a common incoherent bath: this further channel was dubbed dissipative coupling.

Here we report the experimental observation of magnon-phonon hybridization in a 1D magnonic- phononic crystal via time-resolved Magneto-Optical Kerr Effect (tr-MOKE), Brillouin Light Scattering, and micromagnetic simulations, namely the building of a Von Neumann−Wigner hybridization gap in a quasiparticle-quasiparticle system in the solid state. We obtain experimental evidence of the mixture of coherent and dissipative coupling, a condition we dub here mixed coupling. A Hamiltonian model for the hybridized modes corroborates our findings.

Such quantitative information will be crucial for identifying the experimental parameters that continuously tune the coupling in a magneto-mechanical system, transitioning from purely coherent to purely dissipative coupling. Our results suggest magnonic-phononic crystals as ideal platforms to investigate magnon-phonon mixed coupling, and hint to the possibility of novel magnonic-phononic devices.

Moreover, we propose the observed frequency-damping mismatch as an experimental identifier for such mixed coupling: this is not limited to magnon-phonon coupling, rather can be a useful discriminator also for other hybridizing platforms [1].

[1] P. Carrara et al, Phys. Rev. Lett., 132, 216701 (2024)