Electronic congestion in the microchips of the future

May 16, 2012 By Sarah Perrin, Ecole Polytechnique Federale de Lausanne

Credit: 2012 EPFL
(Phys.org) -- Electrons within some materials can stick together like cars on a traffic jam. Swiss researchers studying promising materials for the future of electronics have been able to highlight this phenomenon

Countless researches have been carried out on new promising materials for the world of electronics, such as or molybdenite. Their bi-dimensional structure, that is: consisting of a single layer of atoms, has paved the way to an increasingly advanced of chips, to , as well as to a greater efficiency in . But what about the of these ? Are they as reliable as traditional silicon?

Researchers at the Ultrafast & Electron Scattering laboratory (Lumes) at EPFL have highlighted some situations where the flow of can be disrupted. The results of their study were recently published in the scientific journal PNAS.

The scientists focused on a material with a distinctive structure that causes electrons to move in a single line of atoms. They found that these electrons could sometimes stick together, as it happens in a slowdown caused by a traffic overload on the highway. A "traffic jam" that occurs in the space of a few femtoseconds (10-15 s). This causes the material to pass from being a conductor to becoming an insulator.

This phenomenon can also occur in bi-dimensional materials, for example due to the vibration between two atoms. Additionally, it sometimes happens as a result of defects in the material or due to the presence of impurities like atoms of iron, gold or other metals. Even though they are present in very small quantities, these elements can change, in their surrounding area, the properties of the host material.

Advantage or disadvantage?

"There are so many researches and hopes pinned on low dimensional materials that it is crucial to properly understand their behavior and to be able to identify the microscopic phenomena taking place within them", says Fabrizio Carbone, one of the authors of the research. His work aims to understanding the way these ‘jams’ are formed in order to find means to avoiding or, on the contrary, triggering them. "This kind of disruption can be perceived as a malfunction or as an asset, depending on the application desired for this material," the scientist explains.

If the objective is to take advantage of the material’s property of transitioning from conductor to insulator, provoking or controlling the vibration that triggers such a transition will be required. This can be done by a laser whose wavelength will be determined, or by the intervention of an electric field. On the other hand, if a material with a good conductivity is desired, it will be manufactured so as to eliminate the sources of this vibration. This can be achieved by removing the material’s impurities or by transforming the structure of the unit cell where the are organized.

Explore further: Less is more: Researchers pinpoint graphene's varying conductivity levels

More information: Evidence for a Peierls phase-transition in a three-dimensional multiple charge-density waves solid, PNAS journal, April 2012.

Related Stories

ORNL microscopy explores nanowires' weakest link

February 13, 2012

Individual atoms can make or break electronic properties in one of the world's smallest known conductors—quantum nanowires. Microscopic analysis at the Department of Energy's Oak Ridge National Laboratory is delivering ...

Ultrafast imaging of electron waves in graphene (w/ Video)

November 10, 2010

The fastest "movies" ever made of electron motion have been captured by researchers using the U.S. Department of Energy’s Advanced Photon Source (APS) at Argonne and the Frederick Seitz Materials Research Laboratory ...

Graphene makes light work of aircraft design

June 8, 2010

(PhysOrg.com) -- Faster and lighter aircraft could be built using an incredible super-thin material just one atom thick, according to new research conducted at The University of Manchester.

Recommended for you

CMS gets first result using largest-ever LHC data sample

February 15, 2019

Just under three months after the final proton–proton collisions from the Large Hadron Collider (LHC)'s second run (Run 2), the CMS collaboration has submitted its first paper based on the full LHC dataset collected in ...

Gravitational waves will settle cosmic conundrum

February 14, 2019

Measurements of gravitational waves from approximately 50 binary neutron stars over the next decade will definitively resolve an intense debate about how quickly our universe is expanding, according to findings from an international ...


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.