Skip to Main Content
The subject of this note is the extension of the Nyquist theorem, which relates the electrical noise in a conductor in thermal equilibrium to the Ohmic conductivity,1,2 to the “hot electron” situation in which there is a steady electric field E strong enough to disturb the distribution of electrons among Bloch states and for which the steady current density J will not in general be proportional to E.3 For simplicity, we discuss the fluctuations of velocity, v, for a single electron. For a steady state the time average, equation, of a function ψ of the electron's state is the same as the ensemble average at any instant over all N electrons in the body: ψ̅ = ifψ ψ (ψ).
Note: The Institute of Electrical and Electronics Engineers, Incorporated is distributing this Article with permission of the International Business Machines Corporation (IBM) who is the exclusive owner. The recipient of this Article may not assign, sublicense, lease, rent or otherwise transfer, reproduce, prepare derivative works, publicly display or perform, or distribute the Article.