Self-consistent simulation of quantum shot noise in nanoscale electron devices

Abstract

An approach for studying shot noise in mesoscopic systems that explicitly includes the Coulomb interaction among electrons, by self-consistently solving the Poisson equation, is presented. As a test, current fluctuations on a standard resonant tunneling diode are simulated in agreement with previous predictions and experimental results. The present approach opens a new path for the simulation of nanoscale electron devices, where pure quantum mechanical and Coulomb blockade phenomena coexist.

Applied Bohmian mechanics

“…From a computational viewpoint, the single-particle theory for mesoscopic structures is valid for capturing the basic behavior of RTDs, but not appropriate to describe the totality of the typical behavior of these devices [105][106][107][108]146]. Also in the most idealized case of RTDs, the inclusion of the Coulomb correlation between electrons is enough to spoil the results of the single-particle theory.…”

“…Towards a broader electron device simulation tool, a generalization of the classical ensemble Monte Carlo device simulation technique was proposed to simultaneously deal with quantum-mechanical phase-coherence effects and scattering interactions in quantum-based devices [103][104][105][106][107][108]. The proposed method restricts the quantum treatment of transport to the regions of the device where the potential profile significantly changes in distances of the order of the de Broglie wavelength of the carriers.…”

“…Over the last ten years, as a result of the above mentioned works, Oriols and coworkers have developed a trajectory-based quantum Monte Carlo simulator based on Bohmian mechanics specially designed for the description of electron transport in nanoscale devices, both for DC and beyond DC regimes (see Refs. [103][104][105][106][107][108]136] and a recent review in [124]). The simulator includes also a package based on the semiclassical limit of Bohmian mechanics [137][138][139][140][141] and has been rececently generalized to include spin-dependent electron transport [142].…”

Transport and noise in resonant tunneling diode using self-consistent Green’s function calculation

“…Deviations of the noise from the full (Poissonian) noise value in RTD have been extensively investigated in a great number of works, both theoretical 19,20,22 and experimental. 23,24,25,26,27 Mathematically, the measure of these deviations is the Fano factor F defined as the ratio of the actual noise spectral density to the full shot noise value 2eI, where I is the average current.…”

“…Although the NEGF-method has been used to calculate the noise in various structures, 15,16 to our best knowledge, the present work is the first attempt to use this formalism to show both sub-poissonian and super-poissonian shot noise in RTDs, which is now the subject of great attention, both theoretically 17,18,19,20,21,22 and experimentally. 23,24,25,26,27 The paper is organized as follows.…”