Prem Kumar
For now, full-fledged quantum computers are the stuff of science fiction - in last summer's blockbuster movie Transformers, the bad guys use quantum computing to break into the U.S. Army's secure files in just 10 seconds flat.

But Prem Kumar, the AT&T Professor of Information Technology in the Department of Electrical Engineering and Computer Science and the director of the Center for Photonic Communication and Computing, and his research group are one step closer to realizing that technology - though for far better purposes. The group recently demonstrated one of the basic building blocks for distributed quantum computing using entangled photons generated in optical fibers, and their research was reported in the April 4 edition of Physical Review Letters.

"Because it is done with fiber and the technology that is already globally deployed, we believe that it is a significant step in harnessing the power of quantum computers," Kumar says.

Quantum computing differs from classical computing in that a classical computer works by processing "bits" that exist in two states, either one or zero. Quantum computing uses quantum bits, or qubits, which, in addition to being one or zero can also be in a "superposition," which is both one and zero simultaneously. This is possible because qubits are quantum units like atoms, ions, or photons that operate under the rules of quantum mechanics instead of classical mechanics.........

College Park, MD (June 29, 2010) -- Integrated circuits, which enable virtually every electronics gadget you use on a daily basis, are constantly being pushed by the semiconductor industry to become smaller, faster, and cheaper. As has happened a number of times in the past and will continue in the future, integrated circuit scaling is perpetually in danger of hitting a wall that must be maneuvered around.

As per Maxime Darnon, a researcher at the French National Center for Scientific Research, in order to continue increasing the speed of integrated circuits, interconnect insulators will require an upgrade to porous, low-dielectric constant materials. Darnon and his colleagues discuss the details in the Journal of Applied Physics, which is published by the American Institute of Physics (AIP).

"The integration of a replacement, porous SiCOH (pSiCOH), however, poses serious problems such as an unacceptable 'roughening' that occurs during plasma processing," explains Darnon. "This is considered a 'showstopper' to faster integrated circuits at the moment, so a fundamental understanding of the roughening mechanisms that occur during the etch process of integrated circuit manufacturing is highly desirable to material designers and etch-process engineers.

Darnon's research team proposes a mechanism for the roughening of pSiCOH materials etched in a fluorocarbon-based plasma. They've shown that the problematic roughness results from a cracking of the denser top surface under ion bombardment, and that this roughness propagates through a slower etching of the dense top surface than the modified porous material beneath it. Perhaps more importantly, the team recommends ways to minimize this phenomenon so that the "showstopper" will only be a speedbump on the road to faster integrated circuits.........