https://doi.org/10.1007/s100510050866
Interaction induced delocalization of two particles: large system size calculations and dependence on interaction strength
Laboratoire de Physique
Quantique (UMR C5626 du CNRS) ,
Université Paul Sabatier, 31062 Toulouse Cedex 4, France
Corresponding author: a frahm@irsamc2.ups-tlse.fr
Received:
16
September
1998
Published online: 15 July 1999
The localization length L2 of two interacting particles
in a one-dimensional disordered system is studied for very large
system sizes by an efficient and accurate variant of the Green function
method. The numerical results (at the band center) can be well described
by the functional
form 
where L1 is the one-particle localization
length and the coefficient 
depends on the strength U of the on-site Hubbard interaction.
The Breit-Wigner width or equivalently the (inverse) life time
of non-interacting pair states is analytically
calculated for small disorder and taking into account the energy
dependence of the one-particle localization length.
This provides a consistent theoretical explanation of the numerically
found U-dependence of c(U).
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 72.10.Bg – General formulation of transport theory / 71.55.Jv – Disordered structures; amorphous and glassy solids
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999
