Classical approach to the gap in the tunneling density of states of a two-dimensional electron liquid in a strong magnetic field

A model of a classical electron liquid without external disorder is applied to two-dimensional electrons in a strong magnetic field. Computer modeling gives a quantitative explanation for the recently observed gap in the tunneling current of a double-quantum-well structure. We find that both the Coulomb gap in the single-well density of states and the correlation of electron motion in the two wells are responsible for the tunneling gap. We show that the classical liquid model provides an accurate description of the low-temperature compressibility obtained from a magnetocapacitance experiment.