Exner P.
The absence of the absolutely continuous spectrum for 
delta' Wannier--Stark ladders
(40K, LATEX)

ABSTRACT.  ABSTRACT. A modification of the Kronig-Penney model consisting of
equidistantly spaced delta'-interactions is considered. We
prove that absolutely continuous spectrum of such a system disappears
under influence of an external electric field. The result extends to
periodic lattices of non-identical delta' interactions and
potentials which are lower unbounded and, up to a bounded term, 
asymptotically decreasing with bounded first two derivatives.