The physicists and researchers of UCSB’s Awschalom Group are one step closer to harnessing the potential of quantum computers, according to a paper published on Oct. 14, 2010 in the online version of Science.
UCSB physics and electrical and computer engineering professor David Awschalom and graduate student Bob Buckley have led research into using thin layers of diamond to trap free electrons, bombard them with laser light and thus measure the quantum state of those electrons without destroying the information. According to Awschalom, this breakthrough could be a crucial step in the process of harnessing the power of quantum computing, since scientists have so far been limited in their ability both to read information contained in quantum configurations and to not destroy the configuration in the process.
“Manipulating the quantum state of a single electron in a semiconductor without destroying the information represents an extremely exciting scientific development with potential technological impact,” Awschalom said in a press release.
Awschalom is the head of UCSB’s Center for Spintronics and Quantum Computing, a group that hopes to be at the forefront of quantum-state manipulation and the technologies that result from it.
The possible technological impact of the study could be a new generation of computing with hardware manufactured down to the position of its individual atoms. The processing power of computing is limited by the physical size of the hardware, which is why faster computers always involve tinier and tinier components, and quantum computers work — in theory — with the tiniest of components. This means that if computers can be compacted to a quantum level, their computing power per unit of area would massively increase.
The specific circumstances and conditions Awschalom and Buckley used to achieve their quantum manipulations are what made the breakthrough possible. The researchers used tiny imperfections in layers of diamond where, according to the normal structure of the gem, there ought to have been a carbon atom. When one is replaced by a nitrogen atom, it is called a “nitrogen-vacancy center,” and free electrons can be trapped in its place and bathed in a laser beam. This method, according to Buckley, may allow room temperature observations of quantum effects. However, the current state of the technology still requires cooling the system to a very low temperature.
“Many of the quantum properties of nitrogen-vacancy centers in diamond are observable at room temperature and above, making the nitrogen vacancy center an ideal candidate for many future quantum information applications,” Buckley said in an e-mail. “However, our recent measurements require much colder temperatures in order to quiet down fluctuations of the diamond’s crystal environment. Despite the quantum properties of interest being good at room temperature, our measurements require cryogenic temperatures around 10 Kelvin.”
According to a press release, at a quantum level this combination creates a “light-matter mixture.” This mixture of light and matter allowed the researchers to observe qualities of the light and thus infer the quantum state of the associated electrons.
This breakthrough could — in the far future — mean that a paradigm shift is coming for the computing industry in terms of the materials and mediums of which computers are constructed.
“Diamond may someday become for a quantum computer what silicon is for digital computers today.” Buckley said in a press release. “The building blocks of logic, memory and communication.”
A brighter, sparkly-er future awaits for quantum computing.