Phenomenological Evidence for the Phonon Hall Effect

Strohm, C.; Rikken, G. L. J. A.; Wyder, P.

doi:10.1103/physrevlett.95.155901

Cited by 292 publications

(244 citation statements)

References 20 publications

Supporting

Mentioning

232

Contrasting

Unclassified

Order By: Relevance

“…The combination of the both factors is decisive for the phenomenon under consideration. A novel interesting phenomenon is found experimentally in recent paper [1]. The matter concerns an analog of the anomalous Hall effect (AHE) for the heat conductivity of an ionic paramagnetic dielectric.…”

mentioning

confidence: 98%

“…The heat conduction problem is solved at low temperatures when the heat is carried with long wave acoustic phonons. A fraction of heat flow directed along M × ∇T arises from the elliptic renormalization of the polarization vectors of acoustic phonons with involving (1). The renormalization of the sound velocity does not take place.…”

mentioning

confidence: 99%

“…The elements of density matrix ρ ss ′ ( k) = a + ks a ks ′ off-diagonal in branches and found from the generalized Boltzmann kinetic equation play a key role in the formation of κ ab odd . In recent paper [12] there has been attempted to explain theoretically the phenomenon observed in [1]. Taking SPC in the form analogous to (1), the authors have chosen a simplified model for the phonon spectrum in which two coincident transverse modes always exist for an arbitrary wave vector.…”

mentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

See 3 more Smart Citations

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Kagan

Maksimov²

2008

Phys. Rev. Lett.

107

View full text Add to dashboard Cite

The theory of anomalous Hall effect for the heat transfer in a paramagnetic dielectric, discovered experimentally in [1], is developed. The appearance of the phonon heat flux normal to both the temperature gradient and the magnetic field is connected with the interaction of magnetic ions with the crystal field oscillations. In crystals with an arbitrary phonon spectrum this interaction creates the elliptical polarization of phonons. The kinetics related to phonon scattering induced by the spin-phonon interaction determines an origin of the off-diagonal phonon density matrix. The combination of the both factors is decisive for the phenomenon under consideration. PACS numbers: 66.70.+f, 72.15.Gd, 72.20.Pa A novel interesting phenomenon is found experimentally in recent paper [1]. The matter concerns an analog of the anomalous Hall effect (AHE) for the heat conductivity of an ionic paramagnetic dielectric. In fact, applying magnetic field B in the direction normal to heat flow j, the authors have discovered an appearance of the heat transfer in the direction normal to B and j. For the complete lack of free charged carriers and negligible role of the spin-spin coupling at the parameters concerned, the transverse flow is naturally associated with the evolution of the phonon system. However, the magnetic field does not directly act on phonons and only polarizes paramagnetic ions. It is the coupling between phonons and subsystem of isolated ions carrying magnetic moment M that determines the formation of the picture observed. Note in this aspect that the phenomenon concerned is an analog of the AHE in the paramagnetic phase of a ferromagnetic above the Curie point, discovered a long time ago [2]. An existence of the effect found in [1] has been confirmed in work [3]. In both [1] and [3] the choice of terbium gallium garnet (TbGG) was not accidental. In this compound for T < 10K the heat conductivity due to spin-phonon coupling (SPC) proves to be about two orders of the magnitude smaller as compared with gadolinium garnet [4] of the identical structure.As it is known, in most of ion dielectrics the spinphonon relaxation is determined by the two-phonon processes, see, e.g., [5] and [6]. Usually this supposes the presence of the Kramers doublet in the ground state and the transitions via virtual excitation of higher Kramers doublets. Trivalent ion T b 3+ has the even number of felectrons and the Kramers degeneration is absent. However, for rare earth ions with the even number of felectrons, an appearance of the quasi-doublet structure is typical for splitting the multiplet in the crystalline field with the level spacing ε 12 of about several Kelvins in the ground state. TbGG is a striking example of the similar compound, see, e.g., [7]. From the general symmetry reasons and the direct analysis [8, 9, 10] one can conclude that the SPC under conditions concerned reduces to a scalar production of magnetic moment M and the orbital moment related to the motion of surrounding ions. At low temperatures when the long wave acou...

show abstract

mentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

See 2 more Smart Citations

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Kagan

Maksimov²

2008

Phys. Rev. Lett.

107

View full text Add to dashboard Cite

show abstract

“…Introduction -Recent theoretical advances in applying concepts of topological states of matter to mechanical systems has led to the burgeoning new field of "topological mechanics", where nontrivial topologies of the phonon bands give rise to exotic mechanical and acoustic properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

mentioning

confidence: 99%

Topological Edge Floppy Modes in Disordered Fiber Networks

2018

View full text Add to dashboard Cite

Disordered fiber networks are ubiquitous in a broad range of natural (e.g., cytoskeleton) and manmade (e.g., aerogels) materials. In this paper, we discuss the emergence of topological floppy edge modes in these fiber networks as a result of deformation or active driving. It is known that a network of straight fibers exhibits bulk floppy modes which only bend the fibers without stretching them. We find that, interestingly, with a perturbation in geometry, these bulk modes evolve into edge modes. We introduce a topological index for these edge modes and discuss their implications in biology.

show abstract

Lattice Dynamics, Phonon Chirality, and Spin–Phonon Coupling in 2D Itinerant Ferromagnet Fe₃GeTe₂

Tang

Zhao

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Fe 3 GeTe 2 has emerged as one of the most fascinating van der Waals crystals due to its two-dimensional (2D) itinerant ferromagnetism, topological nodal lines and Kondo lattice behavior. However, lattice dynamics, chirality of phonons and spin-phonon coupling in this material, which set the foundation for these exotic phenomena, have remained unexplored. Here we report the first experimental investigation of the phonons and mutual interactions between spin and lattice degrees of freedom in few-layerFe 3 GeTe 2 . Our results elucidate three prominent Raman modes at room temperature: two A 1g (Γ) and one E 2g (Γ) phonons. The doubly degenerate E 2g (Γ) mode reverses the helicity of incident photon, indicating the pseudo-angular momentum and chirality. Through analysis of temperature-dependent phonon energies and lifetimes, which strongly diverge from the anharmonic model below Curie temperature, we determine the spin-phonon coupling in Fe 3 GeTe 2 . Such interaction between lattice oscillations and spin significantly enhances the Raman susceptibility, allowing us to observe two additional Raman modes at the cryogenic temperature range. In addition, we reveal laser radiation induced degradation of Fe 3 GeTe 2 in ambient conditions and the corresponding Raman fingerprint. Our results provide the first experimental analysis of phonons in this novel 2D itinerant ferromagnet and their applicability for further fundamental studies and application development.

show abstract

Phenomenological Evidence for the Phonon Hall Effect

Cited by 292 publications

References 20 publications

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Topological Edge Floppy Modes in Disordered Fiber Networks

Lattice Dynamics, Phonon Chirality, and Spin–Phonon Coupling in 2D Itinerant Ferromagnet Fe₃GeTe₂

Contact Info

Product

Resources

About

Phenomenological Evidence for the Phonon Hall Effect

Cited by 292 publications

References 20 publications

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Anomalous Hall Effect for the Phonon Heat Conductivity in Paramagnetic Dielectrics

Topological Edge Floppy Modes in Disordered Fiber Networks

Lattice Dynamics, Phonon Chirality, and Spin–Phonon Coupling in 2D Itinerant Ferromagnet Fe3GeTe2

Contact Info

Product

Resources

About

Lattice Dynamics, Phonon Chirality, and Spin–Phonon Coupling in 2D Itinerant Ferromagnet Fe₃GeTe₂