Backscattering in the one-dimensional many-fermion system

Alexander Galea, Tash Zielinski, Stefano Gandolfi +1 more

Carlos Naón, Mariano J. Salvay

We investigate the problem of backscattering off a time-dependent and spatially extended barrier in a one-dimensional noninteracting electron gas. By performing a perturbative expansion in the backscattering amplitude, we compute the total energy density of the system. We show how the free fermion spectrum and the conductance of the system are affected by the interplay between dynamical and geometrical properties of the impurity.

John W. Negele

Manuel Fuentes, Ana Lopez, Eduardo Fradkin

We report exact results for the partition function for free Dirac fermions on a half line with physically sensible boundary conditions. An exact effective action for general backscattering amplitudes is derived. The action also includes the effects of both a (time-dependent) forward scattering amplitude and a dynamical chiral twist of the fermion boundary conditions. For a small backscattering amplitude, the effective action has the expected boundary sine-Gordon form. We discuss applications of our results to one-dimensional Fermi systems with local backscattering. \textcopyright{} 1996 The American Physical Society.

Leon N. Cooper

Daniel Gustavo Barci, L. Moriconi, Marco Moriconi +2 more

We investigate the problem of backscattering off a time-dependent impurity in a one-dimensional electron gas. By combining the Schwinger-Keldysh method with an adiabatic approximation in order to deal with the corresponding out of equilibrium Dirac equation, we compute the total energy density (TED) of the system. We show how the free fermion TED is distorted by the backscattering amplitude and the geometry of the impurity.