Giuseppe Luca Celardo — Università Cattolica del Sacro Cuore #
Zeno dynamics and Cooperative Shielding from long range hopping  in disordered models for quantum transport.  #
We investigate one dimensional disordered  models with both short  (\(\alpha > 1\)) and long range  (\(\alpha<1\)) hopping, 
decaying as \(1/r^{\alpha}\) which are common in many realistic  systems such as  ion traps,  cold atomic clouds and light 
harvesting complexes.
We found, as a consequence of the  long range, an energy gap between the ground state and the other  excited states which 
increases with the system size. Moreover, in the subspace determined by the excited states, the dynamics turns out to be 
shielded from long range in the large system size limit.<br/>
Such <i> Cooperative Shielding</i>, for \(\alpha=0\) can be seen as a kind of Zeno effect and has relevant effects on the 
quantum transport properties.  Indeed even if long range hopping is usually thought to  destroy localization induced by 
the disorder, cooperative shielding allows localization in the  shielded subspace, keeping the ground state  extended in 
the large system size limit.