We discuss the double-time Green’s-function approach for the phonon-phonon interaction in anharmonic solids. Using a certain interpretation of the phonon operators, the crystal Hamiltonian may be rewritten in a compact form. The equation of motion for the Green’s function is tremendously simplified with this formalism. The self-energy can be obtained in a very simple way, to any desired perturbation order. Our results reproduce the corresponding terms of the available literature results, which are limited to the fourth order in the perturbation parameter.
Equation of motion for the Green’s function in anharmonic solids / Raffaele Della Valle;Piero Procacci. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - STAMPA. - 46:(1992), pp. 6141-6149. [10.1103/PhysRevB.46.6141]
Equation of motion for the Green’s function in anharmonic solids
PROCACCI, PIERO
1992
Abstract
We discuss the double-time Green’s-function approach for the phonon-phonon interaction in anharmonic solids. Using a certain interpretation of the phonon operators, the crystal Hamiltonian may be rewritten in a compact form. The equation of motion for the Green’s function is tremendously simplified with this formalism. The self-energy can be obtained in a very simple way, to any desired perturbation order. Our results reproduce the corresponding terms of the available literature results, which are limited to the fourth order in the perturbation parameter.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.