MESOSCOPIC CHARGE QUANTIZATION

We study the Coulomb blockade in a chaotic quantum dot connected to a lead by a single channel at nearly perfect transmission. We take into account quantum fluctuations of the dot charge and a finite level spac ing for electron states within the dot. Mesoscopic fluctuations of the rmodynamic and transport properties in the Coulomb blockade regime exi st at any transmission coefficient. In contrast to the previous theori es, we show that by virtue of these mesoscopic fluctuations, the Coulo mb blockade is not destroyed completely even at perfect transmission. The oscillatory dependence of all the observable characteristics on th e gate voltage is preserved, its period is still defined by the charge of a single electron. However, phases of those oscillations at perfec t transmission are random; because of the randomness, the Coulomb bloc kade shows up not in the averages but in the correlation functions of the fluctuating observables (e.g., capacitance or tunneling conductanc e). This phenomenon may be called ''mesoscopic charge quantization.'' [S0163-1829(98)05316-8].