Understanding the dynamics of atomic vibrations confined in quasi-zero dimensional systems is crucial from both a fundamental point-of-view and a technological perspective. Using ultrafast electron diffraction, we monitored the lattice dynamics of GaAs quantum dots-grown by Droplet Epitaxy on AlGaAs-with sub-picosecond and sub-picometer resolutions. An ultrafast laser pulse nearly resonantly ex...

We treat resonant Raman scattering via the multiphonon exciton transitions in cylindrical quantum dots with a parabolic confinement in the lateral direction and with a finite rectangular interface-barrier confinement in the axial direction. The optical phonons and the electron-phonon interaction are considered within the multimode dielectric model. The model exploits both electrostatic and mech...

The soft character of organic materials leads to strong coupling between molecular, nuclear and electronic dynamics. This coupling opens the way to influence charge transport in organic electronic devices by exciting molecular vibrational motions. However, despite encouraging theoretical predictions, experimental realization of such approach has remained elusive. Here we demonstrate experimenta...

It is a wideheld belief that the holes doped into the CuO2 planes of the cuprate superconductors tend to segregate into stripes that separate antiphase antiferromagnetic domains. However, solid evidence for such stripe order was obtained so far only for the particular compound La1.48Nd0.4Sr0.12CuO4 (LNSCO) and the closely related one La1.875Ba0.125CuO4. In these two compounds, nuclear and magne...

The vibrational properties of clean, Hand D-covered GaN{0001} surfaces were investigated by high-resolution electron energy-loss spectroscopy. Auger electron spectroscopy and low-energy electron diffraction were utilized to monitor the surface cleanliness and structure, respectively. At the clean surface the Fuchs-Kliewer surface phonon frequency was determined to 700 cm−1 (86.8 meV). For the a...

in this study, bio-based carbon nanotubes (cnts) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. new potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. phonons have ...

– The energy spectrum of the quantum Klein-Gordon (KG) lattice is computed numerically for some model parameters that are relevant for optical phonon spectra. A pairing of the phonon states is found when the nonlinearity is significant which agrees with other studies on different quantum lattice models [1,2]. It results from the anharmonic energy contribution the magnitude of which is quantifie...

Organic thin films with semiconducting properties have recently attracted large interest due to novel device possibilities like organic LED, lasers, and solar cells. Particularly attractive for applications are molecules which form quasi-1D crystals: Here, the strong orbital overlap between neighboring molecules favors the generation and transport of charge carriers. However, the phonon propert...

It is known that the temperature-dependent thermal conductivity of conventional crystals follows classical 1/$T$ trend due to dominant umklapp phonon-phonon scattering at high enough temperatures. However, many crystalline metal-organic frameworks very low and shows a weak temperature dependence when all vibrational modes are occupied. By studying two frameworks, i.e., zeolitic imidazolate fram...