Magnon polaron formed by selectively coupled coherent magnon and phonon modes of a surface patterned ferromagnet

Abstract

Strong coupling between two quanta of different excitations leads to the formation of a hybridized state which paves a way for exploiting new degrees of freedom to control phenomena with high efficiency and precision. A magnon polaron is the hybridized state of a phonon and a magnon, the elementary quanta of lattice vibrations and spin waves in a magnetically-ordered material. A magnon polaron can be formed at the intersection of the magnon and phonon dispersions, where their frequencies coincide. The observation of magnon polarons in the time domain has remained extremely challenging because the weak interaction of magnons and phonons and their short lifetimes jeopardize the strong coupling required for the formation of a hybridized state. Here, we overcome these limitations by spatial matching of magnons and phonons in a metallic ferromagnet with a nanoscale periodic surface pattern. The spatial overlap of the selected phonon and magnon modes formed in the periodic ferromagnetic structure results in a high coupling strength which, in combination with their long lifetimes allows us to find clear evidence of an optically excited magnon polaron. We show that the symmetries of the localized magnon and phonon states play a crucial role in the magnon polaron formation and its manifestation in the optically excited magnetic transients.

18 pages, 4 figures + Supplementary materials (available through the corresponding link given in References)

References in corpus (18)

• Magnon-photon-phonon entanglement in cavity magnomechanics
• Acoustically driven ferromagnetic resonance
• Creation and control of multi-phonon Fock states in a bulk acoustic wave resonator
• Spin pumping with coherent elastic waves
• Magnon Polarons in the Spin Seebeck Effect
• Coherent magnetization precession in ferromagnetic (Ga,Mn)As induced by picosecond acoustic pulses
• Ultrafast Magneto-Acoustics in Nickel Films
• Surface acoustic wave driven ferromagnetic resonance in (Ga,Mn)(As,P) epilayers
• Phonon Magnetochiral Effect
• Generation and imaging of magnetoacoustic waves over millimetre distances
• Nonlocal magnon-polaron transport in yttrium iron garnet
• Bottleneck accumulation of hybrid magneto-elastic bosons
• Large non-reciprocal propagation of surface acoustic waves in epitaxial ferromagnetic/semiconductor hybrid structures
• Picosecond acoustic excitation driven ultrafast magnetization dynamics in dielectric Bi-substituted yttrium iron garnet
• Frequency and wavenumber selective excitation of spin waves through coherent energy transfer from elastic waves
• Spin-Wave Modes in Transition from a Thin Film to a Full Magnonic Crystal
• Generation of a localized microwave magnetic field by coherent phonons in a ferromagnetic nanograting
• Optical excitation of single- and multi-mode magnetization precession in Galfenol nanolayers

Cited by in corpus (32)

• Cavity magnomechanics: from classical to quantum
• Advances in coherent coupling between magnons and acoustic phonons
• Straintronics: Manipulating the Magnetization of Magnetostrictive Nanomagnets with Strain for Energy-Efficient Applications
• Magnon-polarons in van der Waals antiferromagnet FePS3
• Microwave-optics Entanglement via Cavity Optomagnomechanics
• Stationary optomagnonic entanglement and magnon-to-optics quantum state transfer via opto-magnomechanics
• Vibronic effects on the quantum tunnelling of magnetisation in Kramers single-molecule magnets
• Bright and dark states of two distant macrospins strongly coupled by phonons
• High pressure tuning of magnon-polarons in the layered antiferromagnet FePS${}_3$
• Magnetization dynamics affected by phonon pumping
• Dynamic Magnetoelastic Boundary Conditions and the Pumping of Phonons
• Real-time non-adiabatic dynamics in the one-dimensional Holstein model: Trajectory-based vs exact methods
• Hybrid topological magnon-phonon modes in honeycomb and kagome lattices
• Tunable topological magnon-polaron states and anomalous Hall phenomena in two-dimensional ferromagnetic insulators
• Giant spin Nernst effect in a two-dimensional antiferromagnet due to magnetoelastic coupling-induced gaps and interband transitions between magnon-like bands
• Effect of magnetic anisotropy relaxation on laser-induced magnetization precession in thin galfenol films
• Composition-tunable magnon-polaron anomalies in spin Seebeck effects in epitaxial Bi${}_x$Y${}_{3-x}$Fe${}_5$O${}_{12}$ films
• Optimizing the magnon-phonon cooperativity in planar geometries
• Coherent strong-coupling of terahertz magnons and phonons in a Van der Waals antiferromagnetic insulator
• Acoustic attenuation in magnetic insulator films: effects of magnon polaron formation
• Neutron Scattering Signature of Phonon Renormalization in Nickel (II) Oxide
• Unidirectional propagation of spin waves excited by femtosecond laser pulses in a planar waveguide
• Computation of High Frequency Magnetoelastic Waves in Layered Materials
• Coherent and dissipative coupling in a magneto-mechanical system
• Magnon-polaron formation in XXZ quantum Heisenberg chains
• Terahertz Control of Linear and Nonlinear Magno-Phononics
• Transition magnon modes in thin ferromagnetic nanogratings
• Superluminal Propagation of Composite Collective Modes in Superconductor-Ferromagnet Heterostructures
• Protected Long-Distance Guiding of Hypersound Underneath a Nano-Corrugated Surface
• Dynamical Orbital Angular Momentum Induced by Circularly Polarized Phonons
• A Narrowband Spintronic Terahertz Emitter based on Magnetoelastic Heterostructures
• Strong coupling between coherent ferrons and cavity acoustic phonons