Resonant tunneling in the quantum Hall regime: Measurement of fractional charge

In experiments on resonant tunneling through a quantum antidot in the quantum Hall (QH) regime, periodic conductance peaks are observed both as a function of magnetic field and back-gate voltage. A combination of the two periods constitutes a measurement of the charge of the tunneling particles and implies that charge deficiency on the antidot is quantized in units of the charge of quasiparticles of the surrounding quantum Hall condensate. The experiment yields values for the electron charge of 1.57 x 10(-19) C= (0.98+/-0.03)e for nu=1 and 2 integer QH, and for the quasi-particle charge 5.20 x 10(-20) C=(0.325+/-0.01)e for nu=1/3 fractional QH effect.