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-sise diagonalisation, we find that its spectral weight is suppressed near sero energy, reaches a minimum at an energy of about 0.2e 2 /el 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 e -ω0/|ω| , for w→0