Physicists detect and control quantum states in diamond with light

October 14, 2010

Physicists at UC Santa Barbara have succeeded in combining laser light with trapped electrons to detect and control the electrons' fragile quantum state without erasing it. This is an important step toward using quantum physics to expand computing power and to communicate over long distances without the possibility of eavesdropping. The work appears online today at Science Express.

The research, led by David Awschalom, professor of physics, electrical and computer engineering, and director of UCSB's Center for and Quantum Computation, and graduate student Bob Buckley, exploits an unusual property of the microscopic quantum world: the ability to combine things that are very different.

Using electrons trapped in a single atom-sized defect within a thin crystal of diamond, combined with laser light of precisely the right color, the scientists showed that it was possible to briefly form a mixture of light and matter. After forming this light-matter mixture, they were able to use measurements of the light to determine the state of the electrons.

Likewise, by separately examining the , they showed that the electron configuration was not destroyed by the light. Instead, it was modified -- a dramatic demonstration of control over quantum states using light. "Manipulating the of a single electron in a semiconductor without destroying the information represents an extremely exciting scientific development with potential technological impact," said Awschalom.

Preserving quantum states is a major obstacle in the nascent field of quantum computing. One benefit of is that it can never be copied, unlike information transferred between today's computers, providing a measure of security that is safeguarded by fundamental laws of nature. The ability to measure a quantum state without destroying it is an important step in the development of technologies that harness the advantages of the quantum world.

Buckley, putting this research in perspective, said: "Diamond may someday become for a quantum computer what silicon is for digital computers today -- the building blocks of logic, memory, and communication. Our experiment provides a new tool to make that happen. "

Explore further: UCSB physicists move one step closer to quantum computing

More information: Research paper: … ract/science.1196436

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not rated yet Oct 18, 2010
With all of this amazing technology being developed in the U.S. why is our economy in the toilet?
not rated yet Oct 19, 2010
With all of this amazing technology being developed in the U.S. why is our economy in the toilet?

It's a bit complicated to explain my point of view on this subject, but in short, the economic model is becoming obsolete.

Regardless of what people have previously claimed, automation is doing away with jobs. Factories today have a handfull to a few dozen workers, whereas even in the recent past to have the same level of production required hundreds of workers. Internet and automated ordering services remove the need for secretaries and other customer service representatives. The list of jobs lost to computers keeps growing.

People can't pay their mortgages unless they have a job. When they lose their houses, and there is zero population growth, then no new houses are needed. This causes more people to lose their jobs because fewer trade and construction workers are needed, and fewer materials are needed so less minining or harvesting of lumber, etc.

not rated yet Oct 19, 2010
Other forms of automation also remove jobs. When a modern lumber company can have one guy on a machine that cuts, strips, debarks, and stacks 100 to 180 trees per hour with just one operator, that's a LOT of jobs that have been lost.

Fewer and fewer people are required to produce the goods and services needed by everyone else. Normally, this wouldn't theoretically be a problem. However, the problem exists because those people who can't get a job because they aren't needed then can't afford to buy anything.

So even though there are a surplus of goods and services, 1/7th of Americans now live in poverty because they can't get a decent job, because their skills are no longer needed, or else because the job they have is considered "unskilled" and therefore doesn't even pay the cost of living, even though nobody else wants to do the job anyway.

"Haves" only pay "Have Nots" as little as they can possibly get away with, and charge them as much as they can possibly get away with...
not rated yet Oct 19, 2010
It's a bit complicated to explain my point of view on this subject
No its not. Your assumption that the world is only as complicated as it can be for you to understand it, exposes both your mistrust of people smarter than you, and of the things which they may create or discover which you cannot.

And so saying something like 'trust me- its a lot more complicated than that' will have absolutely no effect on your perception that you know what is going on (you dont) or on your continued compulsion to leave posts which demonstrate the fact that you obviously do not.
not rated yet Oct 22, 2010
Well put, quantum, but I guess I'm thinking with all this mind blowing technological advancement, it seems like their should be a new "Technological Revolution" (like the Industrial one)-that would revolutionize the world in the same way-and yet it doesn't seem to be materializing. I may not be articulating myself the way I want, I sound more like a Romantic, even to myself...

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