text: Electromigrated nanogaps are gaps formed in metallic bridges formed by the process of electromigration. A nanosized contact formed by electromigration acts like a waveguide for electrons. The nanocontact essentially acts like a one-dimensional wire with a conductance of . The current in a wire is the velocity of the electrons multiplied by the charge and number per unit length,   or . This gives a conductance of . In nano scale bridges the conductance falls in discrete steps of multiples of the quantum conductance .
  Electromigrated Nanogaps have shown great promise as electrodes in use in molecular scale electronics. Researchers have used feedback controlled electromigration to investigate the magnetoresistance of a quantum spin valve.