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Directional routing of one-way classical wave has raised tremendous interests about spin-related phenomena. This sparks specifically the elastic wave study of pseudo-spin in meta-structures to perform robust manipulations. Unlike pseudo-spin in mathematics, the intrinsic spin angular momentum of elastic wave is predicted quite recently which exhibits selective excitation of unidirectional propagation even in conventional solids. However, due to the challenge of building up chiral elastic sources, the experimental observation of intrinsic spin of elastic wave is still missing. Here, we successfully measure the elastic spin in Rayleigh and Lamb modes by adopting elaborately designed chiral meta-sources that excite locally rotating displacement polarization. We observe the unidirectional routing of chiral elastic waves, characterize the different elastic spins along different directions, and demonstrate the spin-momentum locking in broad frequency ranges. We also find the selective one-way Lamb wave carries opposite elastic spin on two plate surfaces in additional to the source chirality.
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http://dx.doi.org/10.1038/s41467-021-27254-z | DOI Listing |
Nat Commun
September 2025
Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany.
Spin-momentum-locked edge states of quantum spin Hall insulators provide a compelling platform for spintronic applications, owing to their intrinsic protection against backscattering from non-magnetic disorder. This protection emerges from time-reversal symmetry, which pairs Kramers partners of helical edge modes with opposite spin and momentum, thereby strictly forbidding elastic single-particle backscattering within the pair. Yet, contrary to the idealized notion of linear edge bands, the non-monotonic dispersions of realistic materials can host multiple Kramers pairs, reintroducing backscattering channels between them without violating time-reversal symmetry.
View Article and Find Full Text PDFRSC Adv
August 2025
Center for Micro and Nano devices (CMND), Comsats University Islamabad Pakistan
Perovskite chalcogenides have attracted significant interest due to their potential applications in optoelectronics, catalysis, and renewable energy systems. This paper examines the structural, electronic, elastic, and phononic properties of KMgX (X = O, S, Se) using density functional theory (DFT) in the context of the full-potential linearized augmented plane wave plus local orbital (FP-LAPW + lo) approach. Their stability in the cubic phase (3̄ symmetry) is confirmed by the computed lattice parameters for KMgO (4.
View Article and Find Full Text PDFJ Phys Condens Matter
August 2025
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, United States of America.
The size and stability of micelles and vesicles determine the uptake capacity of guest molecules, thereby influencing potential applications in drug/gene delivery, bioreactors, and templates for nanoparticle synthesis. Polyethylene glycol (PEG) and polydimethylsiloxane (PDMS) are commonly used in these applications. We discovered that PEG-PDMS-PEG triblock copolymers can assemble into micelles and vesicles, making them valuable for dynamic studies to derive the bending elasticity,κη, which governs the stability these objects.
View Article and Find Full Text PDFPhys Rev Lett
July 2025
Institute of Science Tokyo, Department of Physics, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
The role of the polarization degree of freedom in lattice dynamics in solids has been underlined recently. We theoretically discover a relaxation mechanism for both linear and circular polarizations of acoustic phonons. In the absence of scattering, the polarization exhibits oscillatory behavior.
View Article and Find Full Text PDFNano Lett
August 2025
Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.
Optical properties of the lead halide perovskite nanocrystals are controlled by confined excitons and a rich spectrum of confined acoustic and optical phonons. We study experimentally and theoretically the exciton-phonon interaction in CsPbI perovskite nanocrystals embedded in a glass matrix. Energies of phonon modes allowed by selection rules are detected by resonant Raman scattering for nanocrystals with sizes of 4-13 nm, covering exciton energies of 1.
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