New '1/f noise' discovery promises to improve semiconductor-based sensors

May 09, 2007
New '1/f noise' discovery promises to improve semiconductor-based sensors
Illustration of a Coulomb glass system: Electrons (red) in a random landscape, interacting with each other (yellow-orange lines). Noise of the resistance of the system is created by collective "hopping" of the electrons (green arrow). Credit: Argonne National Laboratory

More sensitive sensors and detectors based on semiconductor electronics could result from new findings by researchers from the United States, Norway and Russia.

Their research has yielded a decisive step in identifying the origin of the universal "one-over-f" (1/f) noise phenomenon; “f” stands for "frequency."

"One-over-f noise appears almost everywhere, from electronic devices and fatigue in materials to traffic on roads, the distribution of stars in galaxies, and DNA sequences," said Valerii Vinokour or Argonne's Materials Science Division. "Finding the common origin of one-over-f noise in its many forms is one of the grand challenges of materials physics. Our theory establishes the origin and lower limit to one-over-f noise in semiconductor electronics, helping to optimize detectors for commercial application."

Noise is a fluctuation in time, a deviation from the average. Humans and other animals carry a common example in their heartbeats, where 1/f noise can be detected as a deviation from normal pulse. In nanomaterials, such as the tiny circuits in semiconductor electronics, the noise generated by the random motion of a single electron can be devastating, since there are so few electrons in the system.

Vinokur and his team showed that the 1/f noise in doped semiconductors, the platform for all modern electronics, originates in the random distribution of impurities and the mutual interaction of the many electrons surrounding them. These two ingredients — randomness and interaction — trap electrons in the Coulomb glass, a state like window glass where electrons move by hopping from one random location to another. 1/f noise arises from the electrons; hopping motion. After discovering the theoretical connection between 1/f noise and formation of the Coulomb glass, Vinokur and his collaborators confirmed it with large-scale computer simulations: suppression of the interactions was found to remove the Coulomb glass behavior and 1/f noise.

“Our results," Vinokour said, "establish that one-over-f noise is a generic property of Coulomb glasses and, moreover, of a wide class of random interacting systems and phenomena ranging from mechanical properties of real materials and electric properties of electronic devices to fluctuations in the traffic of computer networks and the Internet.”

These research findings were published in the May 11 issue of Physical Review Letters.

Source: Argonne National Laboratory

Explore further: It's particle-hunting season! NYU scientists launch Higgs Hunters Project

add to favorites email to friend print save as pdf

Related Stories

And so they beat on, flagella against the cantilever

Sep 16, 2014

A team of researchers at Boston University and Stanford University School of Medicine has developed a new model to study the motion patterns of bacteria in real time and to determine how these motions relate ...

Recommended for you

Particles, waves and ants

Nov 26, 2014

Animals looking for food or light waves moving through turbid media – astonishing similarities have now been found between completely different phenomena.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.