Saturation of phase breaking in an open ballistic quantum dot

One of the key parameters for the observation of quantum interference effects in mesoscopic systems is the phase-breaking time τ_φ. While there have been many measurements of this important phase-breaking time in diffusive mesoscopic structures, there have been relatively few studies of phase breaking in zero-dimensional structures. Here, a saturation of the phase-breaking time at low temperatures is found, with a decay at higher temperatures generally of the form of T^-2/3. Variation with dot size suggests a scaling in which the phase-breaking interaction is described by the total number of electrons N = nA within the dot.