4 papers
Hindered rotators by off-site ions in solids: Optical conductivity by sombrero potentials
I. Polyanski, A. G. Andreev, V. Krastev +2
We consider the optical conductivity of carriers scattered by local sombrero potentials associated with hindered planar rotators in solids. Examples for hindered rotators are provi…
Variational band theory of vibronic polarons in crystals. III. Numerical calculations
M. Georgiev, A. G. Andreev, M. D. Ivanovich
In the preceding Part II, we derived variational equations for the phonon Fourier amplitudes and for the Fourier amplitudes of the fractional contribution of the electronic bands t…
Carbon diffusion in alpha-iron: Evidence for quantum mechanical tunneling
Ludwik Dabrowski, Alexander Andreev, Mladen Georgiev
Recent experimental data on the diffusion coefficient of carbon in alpha-iron below liquid nitrogen temperature (LNT) question the classical approach to the observed temperature de…
Itinerant vibronic polarons: A Merrifield approach I. Low energy range calculations
S. G. Tsintsarska, M. D. Ivanovich, A. Andreev +3
We extend Merrifield's Variational Ansatz in the variational band theory of polarons to cover a frame of two electronic bands mixed by an Einstein phonon. The Hamiltonian is compos…