A state with negative binding energy induced by coherent transport in a   quantum wire
  In a two-dimensional quantum wire in a perpendicular magnetic field with a smooth embedded repulsive scattering potential we find in the multimode conductance resonances caused by bound states with negative binding energy. These resonances are the counterexamples to well known dips in the conductance and evanescent states caused by quasi-bound states of attractive scattering centers in the wire. 
Vidar Gudmundsson, Chi-Shung Tang, and Andrei Manolescu