On the theory of electrical fluctuations

Abstract

In the first part of this paper a critical analysis of the fundamental prmciples of the theory of ‘thermal fluctuations of electricity’ is given, and a new derivation of Nyquist’s theorem is presented which avoids some of the main difficulties encountered by Nyquist’s original work. The chief aim of the second part is to show that the two types of electrical fluctuation phenomena, namely, th£ ‘thermal fluctuation’ and the ‘shot effect', are in fact identical, in spite of the apparently different origin of the fluctuations. For this purpose the methods for the derivation of the expressions for the shot fluctuations and their meaning are critically analyzed, and the reasons discussed which lead to the above-mentioned conclusion. Finally, on the basis of this idea, a tentative derivation of a general formula for the shot-effect in diodes is given which ought to be valid throughout the whole range of the characteristic.