Observation of the $\mathit{e}\mathit{/}3$ Fractionally Charged Laughlin Quasiparticle

The existence of fractional charges carrying current is experimentally demonstrated. Using a 2D electron system in a high perpendicular magnetic field we measure the shot noise associated with tunneling in the fractional quantum Hall regime at Landau level filling factor 1/3. The noise gives a direct determination of the quasiparticle charge, which is found to be $e^{*}=e/3$ as predicted by Laughlin. The existence of $e/3$ Laughlin quasiparticles is unambiguously confirmed by the shot noise to Johnson-Nyquist noise crossover found for temperature $\Theta {=e}^{*}{V}_{\mathrm{ds}}/{2k}_B$.