Tunneling into a two-dimensional electron system in a strong magnetic field

We investigate the properties of the one-electron Green’s function in an interacting two-dimensional electron system in a strong magnetic field, which describes an electron tunneling into such a system. From finite-size diagonalization, we find that its spectral weight is suppressed near zero energy, reaches a maximum at an energy of about 0.2${\mathit{e}}^2$/ε${\mathit{l}}_{\mathit{c}}$, and decays exponentially at higher energies. We propose a theoretical model to account for the low-energy behavior. For the case of Coulomb interactions between the electrons, at even-denominator filling factors such as ν=1/2, we predict that the spectral weight varies as ${\mathit{e}}_0^{\mathrm{-}\mathrm{\omega }}$/‖ω‖, for ω→0.