TUNNELING BETWEEN 2-DIMENSIONAL ELECTRON-SYSTEMS IN A STRONG MAGNETIC-FIELD

We calculate the tunnel current between two parallel two-dimensional electron systems in a strong perpendicular magnetic field. We model the strongly correlated electron systems by Wigner crystals, and describe their low-energy dynamics in terms of magnetophonons. The effects of the magnetophonons on the tunneling processes can be described by an exactly solvable independent-boson model. A tunneling electron shakes up magnetophonons, which results in a conductance peak that is displaced away from zero voltage and broadened compared with the case of no magnetic field. At low temperatures and low enough voltages the tunneling conductance is strongly suppressed, and the I-V characteristics exhibit a power-law behavior. The zero-voltage conductance is thermally activated with an activation temperature similar to 10 K. The results are in very good agreement with experiment.