Discrete breathers above phonon spectrum

V. Hizhnyakov, A. Shelkan, M. Haas, M. Klopov
2016 Letters on Materials  
It is shown that in some metals (Ni, Nb, Fe, Cu) may exist discrete breathers with frequencies above the top of the phonon spectrum. These excitations are mobile: they may propagate along the crystallographic directions transferring energy of > 1 eV over large distances. The discrete breathers with the frequencies above the top of the phonon bands may also exist in covalent crystals (diamond, Si and Ge). It is also found that in monatomic chains and planes (e.g. in graphene), the transverse
more » ... the transverse discrete breathers may be excited above the spectrum of corresponding phonons. Although these vibrations are in resonance with longitudinal (chain) or in-plane (graphene) phonons the lifetime of them may be very long.
doi:10.22226/2410-3535-2016-1-61-72 fatcat:au3o3h53zbbctpqr3tgkmugoa4