We have studied the dependence of noise characteristics on the dimension of electron
confinement of quantum devices at low temperature. By using the nonequilibrium
Green's function method, we have found that in a double barrier resonant tunneling
diode the shot noise is suppressed only around the bias voltage of the resonant
tunneling and the noise suppression is more than half of the full shot noise in case of
symmetric structures with thin barriers. On the other hand, in the Coulomb staircase
characteristics of a quantum dot with equal barriers, the shot noise is suppressed on
an average about half of the full shot noise while further drops are observed at the
current-step voltages.
Enhanced Shot Noise in Resonant Tunneling: Theory and Experiment
