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

TL;DR

This paper investigates how low frequency shot noise and dc current in double-barrier resonant-tunneling structures are affected by strong magnetic fields, revealing their sensitivity to charge accumulation and Landau level broadening.

Contribution

It provides a detailed analysis of shot noise and current profiles in DBRTS under magnetic fields using Keldysh Green's functions, highlighting their dependence on Landau level broadening.

Findings

Noise and current are highly sensitive to bias voltage and magnetic field.

Shot noise spectra reveal information about Landau level broadening.

Different broadening profiles significantly affect noise characteristics.

Abstract

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