Localization and critical diffusion of quantum dipoles in two dimensions.
Phys Rev Lett
; 107(7): 076401, 2011 Aug 12.
Article
in En
| MEDLINE
| ID: mdl-21902407
ABSTRACT
We discuss quantum propagation of dipole excitations in two dimensions. This problem differs from the conventional Anderson localization due to the existence of long-range hops. We find that the critical wave functions of the dipoles always exist which manifest themselves by a scale independent diffusion constant. If the system is T invariant the states are critical for all values of the parameters. Otherwise, there can be a "metal-insulator" transition between this "ordinary" diffusion and the Levy flights (the diffusion constant logarithmically increasing with the scale). These results follow from the two-loop analysis of the modified nonlinear supermatrix σ model.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Rev Lett
Year:
2011
Document type:
Article
Affiliation country: