Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Molecular engineers record an electron's quantum behavior

These images show a diamond sample with a hemispherical lens (right and lower left), and the location of a single electron spin/quantum state visible through its light emission (upper left). The scale bar on the image at upper left measures five microns, the approximate diameter of a red blood cell.

Credit: Courtesy of Awschalom Lab/University of Chicago
These images show a diamond sample with a hemispherical lens (right and lower left), and the location of a single electron spin/quantum state visible through its light emission (upper left). The scale bar on the image at upper left measures five microns, the approximate diameter of a red blood cell.

Credit: Courtesy of Awschalom Lab/University of Chicago

Abstract:
A team of researchers led by the University of Chicago has developed a technique to record the quantum mechanical behavior of an individual electron contained within a nanoscale defect in diamond. Their technique uses ultrafast pulses of laser light both to control the defect's entire quantum state and observe how that single electron state changes over time. The work appears in this week's online Science Express and will be published in print later this month in Science.

Molecular engineers record an electron's quantum behavior

Chicago, IL | Posted on August 14th, 2014

This research contributes to the emerging science of quantum information processing, which demands that science leave behind the unambiguous universe of traditional binary logic—0 or 1—and embrace the counterintuitive quantum world, where behavior is radically different from what humans experience every day. While people are generally content being in one place at a time, electrons can be in many states at once.

The team researches a quantum mechanical property of the electron known as spin. Much like conventional computers use the charge state of electrons to constitute bits of information, a quantum computer would use the spin state of a single electron as its quantum bit, or qubit. The work could accelerate development of quantum computing devices, and the extra computing power that would come with them, because it will be easier to identify materials that have appropriate quantum properties.

The spin system studied is known as the nitrogen-vacancy (NV) center, an atom-sized defect that occurs naturally in diamond, consisting of a nitrogen atom next to a vacant spot in the crystal lattice. "These defects have garnered great interest over the past decade, providing a test-bed system for developing semiconductor quantum bits as well as nanoscale sensors," said team leader David Awschalom, the Liew Family Professor of Molecular Engineering at UChicago. "Here, we were able to harness light to completely control the quantum state of this defect at extremely high speeds."

Quantum snapshots

In this new technique, the researchers locate a single NV center and then illuminate it with a pair of extremely short pulses of laser light. Each pulse lasts less than a picosecond (or a millionth of a millionth of a second). The first pulse excites the quantum states of the defect-bound electron, which then change or evolve in characteristic ways. The second pulse stops that evolution, capturing a picture of the quantum state at that elapsed time.

By progressively extending the elapsed time between the two pulses, the team creates a sequence of quantum-state snapshots—a movie of how the quantum state changes in time. The elapsed time can be as short as femtoseconds (a billionth of a millionth of a second) or as long as nanoseconds (a thousandth of a millionth of a second). On the human scale, this range of time is like the difference between an hour and a century.

Having this vast range of timescales makes the technique especially valuable. The electron is susceptible and interacts with its complex local environment in many different ways, each with a characteristic timescale. Being able to test a wide range of these timescales gives a far more complete picture of the dynamics of the NV center than has been obtained previously.

"Our goal was to push the limits of quantum control in these remarkable defect systems," explained Lee Bassett, co-lead author on the paper and now an assistant professor of electrical and systems engineering at the University of Pennsylvania, "but the technique also provides an exciting new measurement tool. By using pulses of light to direct the defect's quantum dynamics on super-short timescales, we can extract a wealth of information about the defect and its environment."

"It's quite a versatile technique, providing a full picture of the excited state of the quantum defect," said F. Joseph Heremans, a postdoctoral scholar at UChicago, the other co-lead author on the paper. "Previous work on the nitrogen-vacancy center has hinted at some of these processes, but here, simply through the application of these ultrafast pulses, we get a much richer understanding of this quantum beast."

Spin control

It's not just a matter of observation, though. "This technique also provides a means of control of the spin state—an important precursor for any quantum information system," said Evelyn Hu, a professor of applied physics and electrical engineering at Harvard University, who is not connected with the new work.

In addition, the method is not limited to investigating this particular defect. It could be applied to quantum states of matter in a host of materials and technologies, including many semiconductor materials. "You only have to be able to use light to transfer an electron between a ground state and an excited state," said Awschalom.

Professor Guido Burkard, theoretical physicist at the University of Konstanz and a co-author on the paper, remarked, "This technique offers a path toward understanding and controlling new materials at the atomic level."

Hu agrees that the technique opens many new avenues. "Each new system will pose new challenges to understanding the energy levels, local environments, and other properties, but the general approach should provide an enormous step forward for the field," said Hu.

###

In addition to researchers from UChicago's Institute for Molecular Engineering, the team included collaborators at the University of California, Santa Barbara (co-lead author Lee Bassett is now at the University of Pennsylvania), and the University of Konstanz, Germany.

####

For more information, please click here

Contacts:
Steve Koppes
773-702-8366

Copyright © University of Chicago

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

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

NANOPOSTER 2015 - 5th Virtual Nanotechnology Conference - call for abstracts January 24th, 2015

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Spintronics

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014

Pb islands in a sea of graphene magnetise the material of the future December 16th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Quantum Computing

Graphene brings quantum effects to electronic circuits January 22nd, 2015

Improved interface for a quantum internet January 16th, 2015

Rice-sized laser, powered one electron at a time, bodes well for quantum computing January 15th, 2015

Toward quantum chips: Packing single-photon detectors on an optical chip is a crucial step toward quantum-computational circuits January 9th, 2015

Discoveries

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Iranian Scientists Produce Graphene-Based Oxygen Sensor January 23rd, 2015

Silver nanowires demonstrate unexpected self-healing mechanism: The material has potential for flexible electronics January 23rd, 2015

Materials/Metamaterials

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Silver nanowires demonstrate unexpected self-healing mechanism: The material has potential for flexible electronics January 23rd, 2015

Scientists 'bend' elastic waves with new metamaterials that could have commercial applications: Materials could benefit imaging and military enhancements such as elastic cloaking January 23rd, 2015

Announcements

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

NANOPOSTER 2015 - 5th Virtual Nanotechnology Conference - call for abstracts January 24th, 2015

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

New technique helps probe performance of organic solar cell materials January 23rd, 2015

Iranian Scientists Produce Graphene-Based Oxygen Sensor January 23rd, 2015

Silver nanowires demonstrate unexpected self-healing mechanism: The material has potential for flexible electronics January 23rd, 2015

Photonics/Optics/Lasers

Scientists 'bend' elastic waves with new metamaterials that could have commercial applications: Materials could benefit imaging and military enhancements such as elastic cloaking January 23rd, 2015

Teijin to Participate in Nano Tech 2015 January 22nd, 2015

New method to generate arbitrary optical pulses January 21st, 2015

New signal amplification process set to transform communications, imaging, computing: UC San Diego researchers discover a mechanism to amplify signals in optoelectronic systems that is far more efficient than standard processes January 21st, 2015

Research partnerships

Wearable sensor clears path to long-term EKG, EMG monitoring January 20th, 2015

Graphene enables all-electrical control of energy flow from light emitters: First signatures of graphene plasmons at telecommunications wavelength revealed January 20th, 2015

Charge instability detected across all types of copper-based superconductors: Findings may help researchers synthesize materials that can superconduct at room temperature January 16th, 2015

Gold nanoparticles show promise for early detection of heart attacks: NYU School of Engineering Professors collaborate with researchers from Peking University on a new test strip January 15th, 2015

Quantum nanoscience

Graphene brings quantum effects to electronic circuits January 22nd, 2015

Nano-beaker offers insight into the condensation of atoms January 21st, 2015

Atoms can be in 2 places at the same time: Researchers of the University of Bonn have shown that cesium atoms do not follow well-defined paths January 20th, 2015

Two or one splashing? It's different! Physicist at the University of Bonn observe light-matter interaction with two atoms for the first time January 16th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE