Hot electron noise in semiconductors from first principles*

First principles calculations of the properties such as mobility in semiconductors are now routine owing to advances in the ab-initio treatment of the electron-phonon interaction. However, fluctuational properties like the spectral noise power of current fluctuations, which can be calculated from the same ab-initio inputs, are experimentally accessible but yet to be reported. Here, we report an ab initio calculation of the spectral noise power in GaAs using a Boltzmann-Green’s function method. This approach expresses the noise spectral power using the current autocorrelation function computed from solutions of the Boltzmann transport equation with first principles electron-phonon interactions as input. The physical insights yielded by this description of fluctuational properties will help guide the design of semiconductor devices operating closer to the standard quantum limit of noise.