Researcherrs from the University of California (UC Riverside) have finally (after almost a century of research) managed to find out what causes the low-frequency electronic 1/f noise (also known as pink noise or flicker noise). Using graphene sheets, it was found that 1/f noise is a surface phenomenon that shows up in situations that are thinner than 2.5 nm (at least for graphene).

Graphene was essential for this work because you can test for 1/f noise using a single sheet, and then add sheet after sheet (basically adding just one-atom to the thickness of the conductive material). This cannot be done with metal films.

This result also confirms, according to the researchers, that graphene will be a good material for analog circuits and sensors - because these applications require low level of 1/f noise. Using a single sheet of graphene. the total noise consists of the surface noise only.

1/f noise was first observed in vacuum tubes in 1925, and it has been found everywhere - from music recordings to human heart rates, from electrical currents in materials to electronic devices.

Source: 
Tags: