Charging energy of a chaotic quantum dot

The scaling behavior of the charging energy of a quantum dot with asymmetri cally adjusted tunnel barriers is measured through the amplitude of the Cou lomb oscillations in the thermovoltage. For weak coupling between the dot a nd the reservoirs, we observe a linear scaling of the effective charging en ergy when the transmission probability of one tunnel barrier is increased. At higher transmission probabilities, we find a deviation from the linear s caling and a crossover to a constant value. This behavior is caused by the chaotic nature of the electron trajectories within the dot. [S0031-9007(98) 07846-6].