相关论文: Ferroaxial phonons in chiral and polar NiCo2TeO6

Recently, phonons with chirality (chiral phonons) have attracted significant attention. Chiral phonons exhibit angular and pseudo-angular momenta. In circularly polarized Raman spectroscopy, the peak split of the $\Gamma_3$ mode is…

Ferroaxial order is characterized by the breaking of mirror symmetry parallel to the crystallographic principal axis, which often originates from spontaneous rotational distortions of the crystal lattice. Such rotational distortions are, by…

Raman optical activity (ROA), the dependence of Raman intensity on the circular polarization of incident and scattered light, has traditionally been observed in chiral molecules and magnetic materials, where inversion or time-reversal…

Chiral phonons have been identified in several chiral crystals, primarily in those with trigonal symmetry and threefold screw axes. In this study, chiral phonons in CrSi$_2$, a chiral crystal with a sixfold helical structure, were…

Phonons are quanta of lattice vibrations, and their modes (linear, circular, or stationary) are symmetry-determined. Circularly polarized phonons, possessing nonzero angular momentum (AM), have drawn widespread attention recently. Despite…

We have found that the polarization dependence of Raman scattering in organic crystals at finite temperatures can only be described by a fourth-rank formalism. This generalization of the second-rank Raman tensor $\mathcal{R}$ stems from the…

Phonon-polaritons propagating in crystal volume offer the possibility of transferring information throughout matter (via phonons) at high (photon-like) velocity and tunable frequency/wavelength in the far-infrared. However, from the…

In our recent paper [Phys. Rev. B 65, 075316 (2002)], the selection rules for the Raman scattering in spherical nanocrystals are analyzed. Here we show, that a physically expedient choice of the coordinate system, related to the…

We report anomalous circularly polarized Raman spectra of phonons in right- and left-handed quartzes. The phonon branches splitting from the E-mode at a finite wavenumber were found to be chiral with mutually opposite angular momenta. Our…

Truly chiral phonons are lattice eigenmodes that combine broken mirror symmetry with circular atomic motion. They can mediate angular-momentum-selective interactions in quantum materials, yet directly resolving both their chirality and…

The contribution of interface phonons to the first order Raman scattering in nanocrystals with non spherical geometry is analyzed. Interface optical phonons in the spheroidal geometry are discussed and the corresponding Frohlich-like…

Binary compounds $A$Bi ($A$ = K, Rb, Cs) crystallize in P2$_1$/c structure containing both clockwise and anticlockwise chiral chains of Bi atoms. Electronic band structure exhibits the insulating nature of these systems, with the band gap…

Chirality is a manifestation of the asymmetry inherent in nature. It has been defined as the symmetry breaking of the parity of static objects, and the definition was extended to dynamic motion such that true and false chiralities were…

Strong light-matter coupling gives rise to polaritons -- quasiparticles that combine both photonic and material characteristics. Here, we show that polar nanocrystals exhibit structure- and environment-dependent Raman scattering, enabled by…

Chiral phonons are the ones with nonzero polarization and can be observed only via a selective coupling with valley electrons and circularly polarized photons. In such process, a new physical quantity, i.e., pseudo-angular momentum (PAM),…

Chiral phonons were initially proposed and further verified experimentally in two-dimensional (2D) hexagonal crystal lattices. Many intriguing features brought about by chiral phonons are attributed to the pseudo-angular momenta which are…

We present a systematic study of the Raman spectra of optical phonons in graphene monolayers under tunable uniaxial tensile stress. Both the G and 2D bands exhibit significant red shifts. The G band splits into two distinct sub-bands (G+,…

The effects of Fano resonance on the optical chirality of planar plasmonic nanodevices in the visible wavelength range are experimentally observed and theoretically explained. The nanodevice consists of a nanodisk at the center with six…

Materials that exhibit ferroaxial order hold potential for novel multiferroic applications. However, in pure ferroaxials, domains are not directly coupled to stress or static electric field due to their symmetry, limiting the ability to…

Chiral phonons are mirror-symmetric vibrations that correspond to twisting and rotational motions of atoms. In chiral biomolecules, they correspond to low-energy terahertz (THz)-range vibrations of the molecular segments involving dozens of…