Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Spin Doctors: Opening the door to studying new, very fast quantum processes

Ames Lab theoretical physicist Viatcheslav Dobrovitski was recently part of a team that produced and controlled rotations of a single quantum spin at rates less than one trillionth of a second.
Ames Lab theoretical physicist Viatcheslav Dobrovitski was recently part of a team that produced and controlled rotations of a single quantum spin at rates less than one trillionth of a second.

Abstract:
For many exciting applications - from someday building quantum computers to developing ultra-precise magnetometry and improving quantum communication across fiber-optic networks - scientists need to better understand really fast and really small quantum systems. Theoretical physicist Viatcheslav Dobrovitski of DOE's Ames Laboratory recently worked with researchers at Lawrence Berkeley National Laboratory and the University of California Santa Barbara to take a significant step forward in the study of quantum processes.

Spin Doctors: Opening the door to studying new, very fast quantum processes

Ames, IA | Posted on May 11th, 2010

The team produced and controlled coherent rotations of a single quantum spin at rates less than one trillionth of a sec­ond. The group's discoveries, which appeared in a recent issue of Science, open the window to study­ing new, very fast quantum processes that were previ­ously impossible to detect and analyze.

Dobrovitski and his colleagues studied quantum spins in diamond, which can contain imperfections called nitrogen-vacancy, or N-V, centers, using sam­ples grown and characterized by researchers at Law­rence Berkeley National Laboratory. Since atoms in diamond sit very tightly in their positions and respond very weakly to heat or other excitation, the spin of an isolated N-V center can be studied with very little inter­ference from the rest of the world.

Isolating quantum spins is important, because to use spins in applications like quantum communication they must rotate smoothly and predictably to retain their quantum properties. When spins are exposed to outside forces, they can get bumped off their path.

"If we want a spin to go from position ‘a' to position ‘b,' an­other way for us to prevent interference from the outside world is to induce the spin rotation as fast as possible so it doesn't have time to interact with other forces," says Dobrovitski.

So researchers at UCSB, who performed the optical and magnetic measurements for the project, applied short and ex­tremely strong pulses of magnetic field to the spins. Similar, but weaker, pulses are used in conventional electron and nuclear magnetic resonance.

As power was increased, the spins started to exhibit a pattern of fast rotations and stallings, caused by the fast changes of the magnetic field during the pulse.

In conventional resonance experiments, the power of a pulse begins low for a short time, reaches a higher and consistent, level for the majority of the pulse and then drops down for a short time. In that case, the affect of pulses' "heads" and "tails" is not very noticeable compared to the even body of the pulse.

But when the magnetic resonance pulse is large and lasts less than a nanosecond, as occurred in the research by Dobrovitski and his colleagues, the pulse is mostly made up of heads and tails.

"If we want to rotate a spin very fast, we necessarily have to deal with the heads and tails," says Dobrovitski. "Our short, strong pulses will consist of mostly just edges. There's no time for a body of the pulse."

The finding that very fast rotations could be induced using these short pulses was a significant discovery in itself.

"We showed that controlled, coherent spin rotation is pos­sible outside the standard framework of nicely defined, long pulses," says Dobrovitski.

In principle, scientists can create much shorter pulse. But these pulses cannot induce a smooth, coherent rotation of a single spin. The pulses' large power excites a plethora of differ­ent degrees of freedom, and the precious quantum coherence of the spin is lost. Thus, the pulses have to be strong but not too strong. Dobrovitski and his colleagues at UCSB found the "sweet spot" for short, strong pulses.

The research team went on to determine experimentally and theoretically that the spins were most controllable when the short pulses had gradual increases and decreases in power.

"Those kinds of pulses seem to gradually awaken the spin processes," says Dobrovitski. "It's most controllable that way, and we can rotate the spins smoothly and coherently but still do re­ally fast rotations."

Next up for Dobrovitski and the team is studying other fast processes in N-V centers using these fast pulses.

"Before our most recent research, people could not see these processes," says Dobrovitski. "Now that we can see them, it's my job as a theoretical physicist to explain what we see."

####

About Ames Laboratory
Ames Laboratory is a government-owned, contractor-operated research facility of the U.S. Department of Energy that is run by Iowa State University.

For more than 60 years, the Ames Laboratory has sought solutions to energy-related problems through the exploration of chemical, engineering, materials, mathematical and physical sciences. Established in the 1940s with the successful development of the most efficient process to produce high-purity uranium metal for atomic energy, the Lab now pursues a broad range of scientific priorities.

For more information, please click here

Contacts:
Ames Laboratory
111 TASF
Ames, IA 50011-3020
(515) 294-9557

Copyright © Ames Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Quantum Computing

Quantum manipulation: Filling the gap between quantum and classical world April 14th, 2014

Rainbow-catching waveguide could revolutionize energy technologies: By slowing and absorbing certain wavelengths of light, engineers open new possibilities in solar power, thermal energy recycling and stealth technology March 28th, 2014

Could Diamonds Be A Computer’s Best Friend? Landmark experiment reveals the precious gem’s potential in computing March 24th, 2014

Waterloo, Technion Partner to Advance Research, Commercialization March 19th, 2014

Discoveries

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Thinnest feasible membrane produced April 17th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Announcements

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Research partnerships

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor April 8th, 2014

Carbon nanotubes grow in combustion flames April 1st, 2014

Quantum nanoscience

Quantum manipulation: Filling the gap between quantum and classical world April 14th, 2014

Scientists in Singapore develop novel ultra-fast electrical circuits using light-generated tunneling currents April 10th, 2014

Quantum Photon Properties Revealed in Another Particle—the Plasmon April 5th, 2014

Notre Dame researchers provide new insights into quantum dynamics and quantum chaos April 2nd, 2014

NanoNews-Digest
The latest news from around the world, FREE







  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE