Coherent forward scattering peak in 1D and 2D disordered systems
<br>
<br>
As recently discovered <a href="#1">[1]</a>, Anderson localization (AL) in a
bulk disordered system triggers the emergence of a coherent forward scattering
(CFS) peak in momentum space, which twins the well-known coherent backscattering
(CBS) peak observed in weak localization experiments. Going beyond the
perturbative regime, we address here the long-time dynamics of the CFS peak in a
1D and 2D random systems <a href="#2">[2]</a>. Focusing on the 2D case, we show
that CFS generally arises due the confinement of the wave in a finite region of
space, and explain under which conditions it can be seen as a genuine signature
of AL. In the localization regime, our numerical results show that the dynamics
of the CFS peak is governed by the level repulsion between localized states,
with a time scale related to the Heisenberg time. This is in perfect agreement
with recent findings based on the nonlinear sigma model. In the stationary
regime, the width of the CFS peak in momentum space is inversely proportional to
the localization length, reflecting the exponential decay of the eigenfunctions
in real space, while its height is exactly twice the background, reflecting the
Poisson statistical properties of the eigenfunctions.