J. Phys. IV France 12 (2002) Pr9-73
Theory of pseudogaps in charge density waves in application to photo electron spectroscopyS.I. Matveenko1 and S. Brazovskii1, 2
1 L.D. Landau Institute for Theoretical Physics, Kosygina Str. 2, 119334 Moscow, Russia
2 Laboratoire de Physique Théorique et des Modèles Statistiques, CNRS, bâtiment 100, Université Paris-Sud, 91405 Orsay, France
For a one-dimensional electron-phonon system we consider the photon absorption involving electronic excitations within the pseudogap energy range. Within the adiabatic approximation for the electron - phonon interactions these processes are described by ronlinear configurations of an instanton type. We calculate the subgap absorption as it can be observed by means of photo electron or tunneling spectroscopies. In details we consider systems with gapless modes: 1D semiconductors with acoustic phonons and incommensurate charge density waves. We found that below the free particle edge the pseudogap starts with the exponential decrease of transition rates changing to a power law deeply within the pseudogap, near the absolute edge.
© EDP Sciences 2002