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 quasi-particles of the surrounding quantum Hall condensate. The experiment yields values for the electron charge of 1.57×10^-19 C= (0.98±0.03)e for ν=1 and 2 integer QH, and for the quasi-particle charge 5.20×10^-20 C=(0.325±0.01)e for ν=1/3 fractional QH effect.