Paper detail

A classical wave-packet approach to shot noise: power spectrum, Fano factor, and effective charge

The progress in nanofabrication, measurement technology, and mesoscopic transport theory has been expanding the field of shot noise. Although a wave-packet approach to DC shot noise of independent electrons at finite temperature was offered as an intuitive alternative to the sophisticated theories, actual shot noise data often behave more complicated than the derived simple expression. For example, so-called effective charge can deviate from elementary electronic charge due to correlated tunnelings. Also, there are cases where one wishes to know the full spectrum of the shot noise. It will be of great use if a handy method for the shot noise in various experimental situations is available. In this article, a classical wave-packet approach to the shot noise is presented. The classical formulation provides a rigorous yet straightforward formalism to compute the full spectrum and, furthermore, clarifies the structure of Fano factor and effective charge. Additionally, the role of realistic detectors and an application to cross correlation measurements are also discussed. The present method can serve as an intuitive complement to the full quantum mechanical and field theoretical approaches.