TUNNELING INTO A 2-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 0.2e2/epsilonl(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 nu = 1/2, we predict that the spectral weight varies as e(-omega0/Absolute value of omega), for omega --> 0.