  A new thermodynamic phase resulting from the competition between a
commensurate potential and disorder in interacting fermionic or bosonic systems
is predicted. It requires interactions of finite extent. This phase,
intermediate between the Mott insulator and the Anderson insulator, is both
incompressible and has no gap in the conductivity. The corresponding phase is
also predicted for commensurate classical elastic systems in presence of
correlated disorder.

Strongly Correlated Electrons