The existence of fractional charges carrying the current is experimentally demonstrated. Using a 2-D electron system in high 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 cross-over found for temperature e*V/2k.
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