We report on a possibility of efficient engineering of the acoustic phonon energy spectrum in multishell tubular structures produced by a novel high-tech method of self-organization of microand nano-architectures. The strain-driven roll-up procedure paved the way for novel classes of metamaterials such as single semiconductor radial microand nano-crystals and multi-layer spiral microand nano-su...

Using in measurements of the phonon frequencies of bcc Titanium, the lattice dynamical calculations are performed on the same phase by using the Third-neighbour Clark-Gazis-Wallis(CGW) model. The theory is used to compute the phonon dispersion curves, the frequency spectra and the lattice spesific heat of the studied phase. The obtained results are compared with the available experimental data.

We study (inverse) photoemission from systems with strong coupling of doped carriers to phonons. Using an adiabatic approximation, we develop a method for calculating spectra. This method is particularly simple for systems where the electron-phonon coupling can be neglected in the initial state, e.g., the undoped t-J model. The theory then naturally explains why the electron-phonon coupling jus...

Thermal properties and transport control are important for many applications, for example, low thermal conductivity is desirable for thermoelectrics. Knowledge of modewise phonon properties is crucial to identify dominant phonon modes for thermal transport and to design effective phonon barriers for thermal transport control. In this paper, we adopt time-domain (TD) and frequency-domain (FD) no...

The following dissertation presents a comprehensive study of the interaction between Dirac fermion quasiparticles (DFQs) and surface phonons on the surfaces of the topological insulators Bi2Se3 and Bi2Te3. Inelastic helium atom surface scattering (HASS) spectroscopy and time of flight (TOF) techniques were used to measure the surface phonon dispersion of these materials along the two high-symme...