AI Article Synopsis
Article Abstract
The coherent vibrational dynamics of Au(SCH), obtained from femtosecond time-resolved transient absorption spectroscopy, are described. Two acoustic modes were identified and assigned, including 2.0 THz breathing and 0.7 THz quadrupolar vibrations. These assignments are consistent with predictions using classical mechanics models, indicating that bulk models accurately describe the vibrational properties of Au(SCH). Coherent phonon signals were persistent for up to 3 ps, indicating energy dissipation by the nanocluster was the primary dephasing channel. The initial excitation phases of the breathing and quadrupolar modes were π-phase-shifted, reflecting differences in the displacive nuclear motion of the vibrations. The combined agreement of the vibrational frequencies, relative phases, and decoherence times supported predictions based on classical models. The vibrational frequencies were insensitive to silver substitution for gold but did show increased inhomogeneous damping of the coherent phonons. The ability to predict the vibrational properties of metal nanoclusters can have an impact on nanoresonator and mass sensing technologies.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.3c01477 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Moisture-Dependent Vibrational Dynamics and Phonon Transport in Nanocellulose Materials.
Adv Mater
December 2024
Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden.
Superinsulating nanofibrillar cellulose foams have the potential to replace fossil-based insulating materials, but the development is hampered by the moisture-dependent heat transport and the lack of direct measurements of phonon transport. Here, inelastic neutron scattering is used together with wide angle X-ray scattering (WAXS) and small angle neutron scattering to relate the moisture-dependent structural modifications to the vibrational dynamics and phonon transport and scattering of cellulose nanofibrils from wood and tunicate, and wood cellulose nanocrystals (W-CNC). The moisture interacted primarily with the disordered regions in nanocellulose, and WAXS showed that the crystallinity and coherence length increased as the moisture content increased.
View Article and Find Full Text PDFDFT-based calculation of vibrational sum frequency generation spectral features of crystalline β-sheets in silk: Polarization and azimuth angle dependences.
J Chem Phys
December 2024
Department of Chemical Engineering, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Sum frequency generation (SFG) necessitates both noncentrosymmetry and coherence over multiple length scales. These requirements make vibrational SFG spectroscopy capable of probing structural information of noncentrosymmetric organic crystals interspersed in polymeric matrices and their three-dimensional spatial distributions within the matrices without spectral interferences from the amorphous components. However, this analysis is not as straightforward as simple vibrational spectroscopy or scattering experiments; it requires knowing the molecular hyperpolarizability of SFG-active vibrational modes and their interplay within the coherence length.
View Article and Find Full Text PDFDeciphering between enhanced light emission and absorption in multi-mode porphyrin cavity polariton samples.
Nanophotonics
June 2024
Materials Structural Dynamics Laboratory, Department of Chemistry, Wayne State University, 48202, Detroit, MI, USA.
It remains unclear how the collective strong coupling of cavity-confined photons to the electronic transitions of molecular chromophore leverages the distinct properties of the polaritonic constituents for future technologies. In this study, we design, fabricate, and characterize multiple types of Fabry-Pérot (FP) mirco-resonators containing copper(II) tetraphenyl porphyrin (CuTPP) to show how cavity polariton formation affects radiative relaxation processes in the presence of substantial non-Condon vibronic coupling between two of this molecule's excited electronic states. Unlike the prototypical enhancement of Q state radiative relaxation of CuTPP in a FP resonator incapable of forming polaritons, we find the light emission processes in multimode cavity polariton samples become enhanced for cavity-exciton energy differences near those of vibrations known to mediate non-Condon vibronic coupling.
View Article and Find Full Text PDFQuantized Acoustoelectric Floquet Effect in Quantum Nanowires.
Phys Rev Lett
November 2024
Department of Physics, IQIM, California Institute of Technology, Pasadena, California 91125, USA.
External coherent fields can drive quantum materials into nonequilibrium states, revealing exotic properties that are unattainable under equilibrium conditions-an approach known as "Floquet engineering." While optical lasers have commonly been used as the driving fields, recent advancements have introduced nontraditional sources, such as coherent phonon drives. Building on this progress, we demonstrate that driving a metallic quantum nanowire with a coherent wave of terahertz phonons can induce an electronic steady state characterized by a persistent quantized current along the wire.
View Article and Find Full Text PDFMultiple coherent radiations are achieved in a water-3-aminopropanol (3AP) mixed solution through cascaded four-wave mixing (C-FWM) and cascaded Stokes (C-Stokes) processes, both driven by stimulated Raman scattering (SRS) in this work. The O-H vibration peak from water is replaced by the emergence of the -NH symmetric stretching Raman peaks from 3AP, with intensity approaching that of the -CH symmetric stretching peak. The dual-wavelength SRS signals for the -NH and -CH stretching vibrations have a relatively small frequency interval of about 400 cm (16 nm).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!