Low-frequency shot noise in double-barrier resonant-tunnelling structures in a strong magnetic field

Abstract

Low frequency shot noise and dc current profiles for a double-barrier\nresonant-tunneling structure (DBRTS) under a strong magnetic field applied\nperpendicular to the interfaces have been studied. Both the structures with 3D\nand 2D emitter have been considered. The calculations, carried out with the\nKeldysh Green's function technique, show strong dependencies of both the\ncurrent and noise profiles on the bias voltage and magnetic field. The noise\nspectrum appears sensitive to charge accumulation due to barriere capacitances\nand both noise and dc-current are extremely sensitive to the Landau levels'\nbroadening in the emitter electrode and can be used as a powerful tool to\ninvestigate the latter. As an example, two specific shapes of the levels'\nbroadening have been considered - a semi-elliptic profile resulting from\nself-consistent Born approximation, and a Gaussian one resulting from the\nlowest order cumulant expansion.\n