Non-Gaussian noise in quantum wells

A. Ben Simon, Y. Paltiel, G. Jung, H. Schneider

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Gaussian generation-recombination is accepted to be a dominant mechanism of current noise source in quantum well systems biased by electric field normal to the layers. Recent experiments in n-type and p-type multiple quantum wells have revealed an additional pronouncedly non-Gaussian excess current noise with a low cut-off frequency in the kHz range. The non-Gaussian noise has been attributed to metastable spatial configurations of electric field. The metastability is originating from negative differential conductance caused by intervalley scattering in n-type wells and heavy and light holes tunneling in p-type wells. At a constant bias the system randomly switches between high resistivity state with low current flow and low resistive state with high current. The non-Gaussianity of the noise is more pronounced in p-type wells where the time traces of current fluctuations resemble closely two-level random telegraph signal. In n-type wells the telegraph-like fluctuations have not been straightforwardly observed. The non-Gaussianity of the noise in n-type systems has been revealed by nonzero skewness. The differences between noise properties of between n- and p-type systems have been attributed to small capture probability of electrons in n-type wells, as opposed to very high capture probability of holes in p-type wells. As a consequence the noise of any p-type multi-well system is dominated by the tunneling from the wells while in the n-type the noise appears as a superposition of many fluctuators associated with individual wells.

Original languageEnglish
Title of host publicationNoise and Fluctuations in Circuits, Devices, and Materials
DOIs
StatePublished - 23 Nov 2007
EventNoise and Fluctuations in Circuits, Devices, and Materials - Florence, Italy
Duration: 21 May 200724 May 2007

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6600
ISSN (Print)0277-786X

Conference

ConferenceNoise and Fluctuations in Circuits, Devices, and Materials
Country/TerritoryItaly
CityFlorence
Period21/05/0724/05/07

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