Electron spectral function of an interacting two dimensional electron gas in a strong magnetic field

The electron spectral function of a 2D interacting electron system in a strong magnetic field is found to exhibit an energy gap at arbitrary filling fractions. In general, this gap is larger than the energy cost associated with a charge e excitation. At this ν=1/2 filling fraction, a numerical estimate of the tunneling gap is ${\mathrm{\Delta }}_{\mathrm{tun}}$=(3.0±0.1)${\mathit{e}}^2$/ε${\mathit{l}}_{\mathit{B}}$ for the Coulomb interaction.