R. Haussmann, ELECTRONIC SPECTRAL-FUNCTION FOR A 2-DIMENSIONAL ELECTRON-SYSTEM IN THE FRACTIONAL QUANTUM HALL REGIME, Physical review. B, Condensed matter, 53(11), 1996, pp. 7357-7375
A two-dimensional system of interacting electrons is considered in a s
trong magnetic field in the fractional quantum Hall regime, where the
motion of the electrons is restricted to the lowest Landau level in th
e lowest subband. Starting from a microscopic quantum-field theory we
present a calculation of the electronic spectral function A(epsilon) f
or a Single layer. From the original Coulomb interaction we separate a
n effective bosonic paa, which is treated exactly by resummation of Fe
ynman diagrams. For the electron Green's function G(tau-tau'), which i
s closely related to A(epsilon), we derive an approximate formula that
goes beyond perturbation theory and is similar to the solution of an
independent-boson model. The independent bosons are the collective exc
itations, mainly magnetorotons. Constructing a bosonic spectral functi
on with the main features of the collective excitations by the single-
mode approximation, we obtain a spectral function A(epsilon) with a do
uble-peak structure and a pseudogap at epsilon approximate to mu for l
ow temperatures. From this result we derive the current-voltage charac
teristic I(V) for the tunneling of electrons between two layers, which
shows a tunneling pseudogap for low temperatures and agrees with rece
nt experiments.