Featured Research

from universities, journals, and other organizations

Physicists identify room temperature quantum bits in widely used semiconductor

Date:
November 3, 2011
Source:
University of California - Santa Barbara
Summary:
Physicists may have earned silicon carbide –– a semiconductor commonly used by the electronics industry –– a role at the center of a new generation of information technologies designed to exploit quantum physics for tasks such as ultrafast computing and nanoscale sensing.

William Koehl
Credit: George Foulsham, Office of Public Affairs, UCSB

A discovery by physicists at UC Santa Barbara may earn silicon carbide -- a semiconductor commonly used by the electronics industry -- a role at the center of a new generation of information technologies designed to exploit quantum physics for tasks such as ultrafast computing and nanoscale sensing.

The research team discovered that silicon carbide contains crystal imperfections that can be controlled at a quantum mechanical level. The finding is published this week in the journal Nature.

The research group of David Awschalom, senior author, made the finding. Awschalom is director of UCSB's Center for Spintronics & Quantum Computation, professor of physics, electrical and computer engineering, and the Peter J. Clarke Director of the California NanoSystems Institute.

In conventional semiconductor-based electronic devices, crystal defects are often deemed undesirable because of their tendency to immobilize electrons by "trapping" them at a particular crystal location. However, the UCSB team discovered that electrons that become trapped by certain imperfections in silicon carbide do so in a way that allows their quantum states to be initialized, precisely manipulated, and measured using a combination of light and microwave radiation. This means that each of these defects meets the requirements for use as a quantum bit, or "qubit," which is often described as the quantum mechanical analog of a transistor, since it is the basic unit of a quantum computer.

"We are looking for the beauty and utility in imperfection, rather than struggling to bring about perfect order," said Awschalom, "and to use these defects as the basis for a future quantum technology."

Most crystal imperfections do not possess these properties, which are intimately tied to the atomic structure of a defect and the electronic characteristics of its semiconductor host, explained Awschalom. In fact, before this research, the only system known to possess these same characteristics was a flaw in diamond known as the nitrogen-vacancy center.

The diamond nitrogen-vacancy center is renowned for its ability to function as a qubit at room temperature, while many other quantum states of matter require an extremely cold temperature, near absolute zero. However, this center exists in a material that is difficult to grow and challenging to manufacture into integrated circuits.

In contrast, high-quality crystals of silicon carbide, multiple inches in diameter, are commonly produced for commercial purposes. They can be readily fashioned into a multitude of intricate electronic, optoelectronic, and electromechanical devices. In addition, the defects studied by Awschalom and his group are addressed using infrared light that is close in energy to the light used widely throughout modern telecommunications networks. And while several distinct defect types were studied at a range of temperatures, two of them were capable of room temperature operation, just like the diamond nitrogen-vacancy center.

The combination of these features makes silicon carbide, with its defects, an attractive candidate for future work seeking to integrate quantum mechanical objects with sophisticated electronic and optical circuitry, according to the researchers. This research fits within a wider effort at UCSB to engineer quantum devices by fostering collaboration between the fields of materials science and quantum physics.

While defects in silicon carbide may offer many technologically attractive qualities, an immense number of defects in other semiconductors are still left to be explored.

"Our dream is to make quantum mechanics fully engineerable," said William Koehl, lead author and a graduate student in the Awschalom lab. "Much like a civil engineer is able to design a bridge based on factors such as load capacity and length span, we'd like to see a day when there are quantum engineers who can design a quantum electronic device based on specifications such as degree of quantum entanglement and quality of interaction with the surrounding environment."


Story Source:

The above story is based on materials provided by University of California - Santa Barbara. Note: Materials may be edited for content and length.


Journal Reference:

  1. William F. Koehl, Bob B. Buckley, F. Joseph Heremans, Greg Calusine, David D. Awschalom. Room temperature coherent control of defect spin qubits in silicon carbide. Nature, 2011; 479 (7371): 84 DOI: 10.1038/nature10562

Cite This Page:

University of California - Santa Barbara. "Physicists identify room temperature quantum bits in widely used semiconductor." ScienceDaily. ScienceDaily, 3 November 2011. <www.sciencedaily.com/releases/2011/11/111102161257.htm>.
University of California - Santa Barbara. (2011, November 3). Physicists identify room temperature quantum bits in widely used semiconductor. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2011/11/111102161257.htm
University of California - Santa Barbara. "Physicists identify room temperature quantum bits in widely used semiconductor." ScienceDaily. www.sciencedaily.com/releases/2011/11/111102161257.htm (accessed April 25, 2014).

Share This



More Computers & Math News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will New FCC Rules Trigger Death Of Net Neutrality?

Will New FCC Rules Trigger Death Of Net Neutrality?

Newsy (Apr. 24, 2014) The Federal Communications Commission will reportedly propose new rules for Net neutrality that could undermine the principles of a free and open Web. Video provided by Newsy
Powered by NewsLook.com
Apple Beats Estimates, Most Looking to Second Half of 2014

Apple Beats Estimates, Most Looking to Second Half of 2014

TheStreet (Apr. 24, 2014) TheStreet's Stephanie Link and Real Money Contributor Dan Nathan discuss Apple's first quarter results. Link and Nathan expected the tech giant to lower guidance for the current quarter which they felt could send shares lower and present a buying opportunity. Nathan says options are cheap because Apple has been aggressively buying back shares. Video provided by TheStreet
Powered by NewsLook.com
Raw: Obama Plays Soccer With Japanese Robot

Raw: Obama Plays Soccer With Japanese Robot

AP (Apr. 24, 2014) President Obama briefly played soccer with a robot during his visit to Japan on Thursday. The President has been emphasizing technology along with security concerns during his visit. (April 24) Video provided by AP
Powered by NewsLook.com
US Proposes Pay-for-Priority Internet Standards

US Proposes Pay-for-Priority Internet Standards

AP (Apr. 24, 2014) The Federal Communications Commission is set to propose new rules that would allow Internet service providers to charge content companies for faster delivery of their services over the so-called "last mile" connection to people's homes. (April 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins