A softening of phonon-dispersion has been observed experimentally in under-doped cuprate superconductors at the charge-density wave (CDW) ordering vector. Interestingly, occurs below superconducting (SC) transition temperature T$_{c}$, contrast to metallic systems, where usually CDW onset T$_{\text{CDW}}$. An understanding `anomalous' nature phonon-softening and its connection pseudo-gap phase ...

The investigations performed in this work primarily deal with the question whether or no phonon±plasmon coupling along the c-axis in metallic La2CuO4 will occur in case a realistic electronic bandstructure based on the local density approximation (LDA) is employed for the calculation of the electronic polarizability P and the dielectric matrix e. Phonon±plasmon mixing will appear in a significa...

We derive the phonon damping rate due to the four-phonon Landau-Khalatnikov process in low temperature strongly interacting Fermi gases using quantum hydrodynamics, correcting and extending the original calculation of Landau and Khalatnikov [ZhETF, 19 (1949) 637]. Our predictions can be tested in state-of-the-art experiments with cold atomic gases in the collisionless regime. Introduction. – Ph...

Electronic and phononic states and their interactions in one-dimensional arrays of Si quantum dots interconnected with thin oxide layers is theoretically investigated. Electronic states under low electric field condition are obtained in the Kronig-Penny potential. Approximate expression for phonon wave functions is developed and numerically calculated using the linear atomic chain model. Simula...