Featured Research

from universities, journals, and other organizations

Bridge to the quantum world: Dirac electrons found in unique material

Date:
December 4, 2012
Source:
University of Michigan
Summary:
In a discovery that helps clear a new path toward quantum computers, University of Michigan physicists have found elusive Dirac electrons in a superconducting material.

In a discovery that helps clear a new path toward quantum computers, University of Michigan physicists have found elusive Dirac electrons in a superconducting material.

Related Articles


Quantum computers use atoms themselves to perform processing and memory tasks. They promise dramatic increases in computing power because of their ability to carry out scores of calculations at once. They could factor numbers dramatically faster than conventional computers, and would be game-changers for computer security.

The combination of properties the researchers identified in a shiny, black material called copper-doped bismuth selenide adds the material to an elite class that could serve as the silicon of the quantum era. Copper-doped bismuth selenide is a superconducting material.

Superconductors can -- at cold enough temperatures -- conduct electricity indefinitely from one kickstart of energy. They have no electrical resistance. Dirac electrons, named after the English physicist whose equation describes their behavior, are particles with such high energy that they straddle the realms of classical and quantum physics.

"They're a bridge between the worlds," said Lu Li, assistant professor of physics in the College of Literature, Science, and the Arts and leader of a study published in the current edition of Physical Review Letters.

Other research teams had theorized that copper-doped bismuth selenide contained Dirac electrons, but no one had ever detected them. Li and his colleagues were able to observe the electrons' tell-tale quantum oscillations in the material by cooling it to cryogenic temperatures and exposing it to a strong magnetic field. Materials rotate under intense magnetic fields, and the researchers could detect the quantum oscillations by varying the strength of the magnetic field and the temperature.

In quantum computers, "qubits" stand in for the 0s and 1s of conventional computers' binary code. A conventional bit can be either a 0 or a 1. A qubit can be both at the same time -- until you measure it. Measuring a quantum system perturbs it into picking just one phase, which eliminates its most enticing attribute.

As one of the major hurdles to developing practical quantum computers, research groups are exploring ways to get around this so-called "local noise" problem. The new class of materials that copper-doped bismuth selenide belongs to -- topological superconductors -- present a new possibility. The Dirac electrons within them have the ability to clump together into a new kind of qubit that changes the properties of the material in a way that's detectable to an observer, but not to the qubits. So the qubits can carry on calculating without knowing they're being measured.

"Schrödinger's cat can stay alive and dead at the same time," said Li, referring to Austrian physicist Erwin Schrödinger's famous thought experiment about quantum mechanics. "The so-called qubit is no longer the object we're looking at. This material could be a promising way to make quantum computers."

In addition to Li, the research team includes Benjamin Lawson, U-M doctoral student in physics and Yew San Hor, assistant professor of physics at Missouri University of Science and Technology. The research was funded by U-M and Missouri S&T. A portion of the work was performed at the National High Magnetic Field Laboratory in Florida.


Story Source:

The above story is based on materials provided by University of Michigan. The original article was written by Nicole Casal Moore. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ben Lawson, Y. Hor, Lu Li. Quantum Oscillations in the Topological Superconductor Candidate Cu_{0.25}Bi_{2}Se_{3}. Physical Review Letters, 2012; 109 (22) DOI: 10.1103/PhysRevLett.109.226406

Cite This Page:

University of Michigan. "Bridge to the quantum world: Dirac electrons found in unique material." ScienceDaily. ScienceDaily, 4 December 2012. <www.sciencedaily.com/releases/2012/12/121204145653.htm>.
University of Michigan. (2012, December 4). Bridge to the quantum world: Dirac electrons found in unique material. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2012/12/121204145653.htm
University of Michigan. "Bridge to the quantum world: Dirac electrons found in unique material." ScienceDaily. www.sciencedaily.com/releases/2012/12/121204145653.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) — With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) — A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) — Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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