Ambipolar Drift Noise in a Semiconductor in the Presence of a Magnetic Field

Abstract

The noise spectrum due to fluctuations of electron-hole pairs in a semiconductor in the presence of uniform and time-independent electric and magnetic fields is presented in this paper. This spectrum is obtained via the Green's function for the macroscopic differential equation which governs the behavior of the conditional average for fluctuations in the electron-hole pair particle density when generation-recombination and ambipolar drift are the only important processes. For the general situation when the electric and magnetic fields are not collinear, the obtained spectrum is a complicated function of both frequency and magnetic field for a fixed value of electric field. From this spectrum the spectra corresponding to the special cases when the electric field is parallel and perpendicular to the magnetic field are obtained. Since the case when the electric field is perpendicular to the magnetic field is the most interesting from an experimental viewpoint, it is discussed in more detail and illustrative plots of the spectrum are presented.