Navigation Links
Light touch: Controlling the behavior of quantum dots
Date:8/19/2008

Researchers from the National Institute of Standards and Technology (NIST) and the Joint Quantum Institute (JQI), a collaborative center of the University of Maryland and NIST, have reported a new way to fine-tune the light coming from quantum dots by manipulating them with pairs of lasers. Their technique, published in Physical Review Letters,* could significantly improve quantum dots as a source of pairs of entangled photons, a property with important applications in quantum information technologies. The accomplishment could accelerate development of powerful advanced cryptography applications, projected to be a key 21st-century technology.

Entangled photons are a peculiar consequence of quantum mechanics. Tricky to generate, they remain interconnected even when separated by large distances. Merely observing one instantaneously affects the properties of the other. The entanglement can be used in quantum communication to pass an encryption key that is by its nature completely secure, as any attempt to eavesdrop or intercept the key would be instantly detected. One goal of the NIST-JQI team is to develop quantum dots as a convenient source of entangled photons.

Quantum dots are nanoscale regions of a semiconductor material similar to the material in computer processors but with special properties due to their tiny dimensions. Though they can be composed of tens of thousands of atoms, quantum dots in many ways behave almost as if they were single atoms. Unfortunately, almost is not good enough when it comes to the fragile world of quantum cryptography and next-generation information technologies. When energized, a quantum dot emits photons, or particles of light, just as a solitary atom does. But imperfections in the shape of a quantum dot cause what should be overlapping energy levels to separate. This ruins the delicate balance of the ideal state required to emit entangled photons.

To overcome this problem, the NIST-JQI team uses lasers to precisely control the energy levels of quantum dots, just as physicists have been doing with actual single atoms since the mid-1970s and, much more recently, with the artificial quantum dot variety. With their customized set-up, which includes two lasersone shining from above the quantum dot and the other illuminating it from the sidethe researchers were able to manipulate energy states in a quantum dot and directly measure its emissions. By adjusting the intensity of the laser beams, they were able to correct for imperfection-caused variations and generate more ideal signals. In so doing, the team was the first to demonstrate that laser-tuned quantum dots can efficiently generate photons one at a time, as required for quantum cryptography and other applications.

While the device currently still requires quite cold temperatures and sits in a liquid helium bath, it is compact enough to fit in the palm of your handan elegant setup that could be eventually implemented in quantum cryptography applications.


'/>"/>

Contact: Mark Bello
mark.bello@nist.gov
301-975-3776
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology technology :

1. Dendreon Announces Publication of Phase 1 Study Highlighting Immunologic and Clinical Activity of Lapuleucel-T (Neuvenge(R)) in Advanced Breast Cancer Patients
2. ImmuneRegen BioSciences Files 8-K that Highlights Enclosed Shareholder Letter Discussing Recent Achievements and Outlook
3. Safety Profile of TAXUS(R) Liberte(TM) Stent System Highlighted in Worlds Largest Stent Registry
4. Stimuvax(R) Phase II data highlight three-year survival results for patients with non-small cell lung cancer
5. Three Studies by Independent Scientists Highlighting Pressure Cycling Technology (PCT) to be Presented this Week at the British Mass Spectrometry Societys 29th Annual Meeting
6. Access Highlighted in Recent BusinessWeek Article
7. Lighting the Onco-Pipeline, Stem Cell Cancer, and More at Global Cancer Congress, January 28-29, 2008, Tampa
8. Highlights of Economic and Business Growth in the Tampa Bay Region
9. Respironics Acquires Apollo Light Systems, Inc., Expands into Circadian Rhythm Device-Based Therapy Market
10. Americas Heartland Launches Third Season Highlighting Contributions of American Farmers and Ranchers
11. CU researchers shed light on light-emitting nanodevice
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Light touch: Controlling the behavior of quantum dots
(Date:5/19/2016)... 19, 2016  AdvancedFlow Systems Inc. (AFS), a ... out of Maple Ridge, British Columbia ... its existing portfolio of contract manufacturing clients by ... with its sister companies Surround Technologies (STI) and ... industrial group that specializes in providing contract manufacturing ...
(Date:5/19/2016)... 19, 2016 - I dati ... durante il 52 ° Congresso ... - Le conclusioni dello studio indicano un ... trattati, di cui il 90% presenta una d urata ... più. Il settantadue per cento dei pazienti ha riscontrato un ...
(Date:5/18/2016)... ... , ... STACS DNA Inc., the sample tracking software company, today announced that ... processing to help them save time and reduce errors. , Sexual Assault kits are ... and victims informed of results. Due to a previous lack of tools, many forensic ...
(Date:5/17/2016)... 2016 Haselmeier announces the launch ... approval by EMA, the European Medicines Agency. Originally launched ... company, the new pen version includes enhancements to further ... confidence to patients during use. Its enhanced ... to handle with a larger display window that improves ...
Breaking Biology Technology:
(Date:3/31/2016)... 31, 2016  Genomics firm Nabsys has completed a ... Barrett Bready , M.D., who returned to the company ... technical leadership team, including Chief Technology Officer, John ... Steve Nurnberg and Vice President of Software and Informatics, ... Dr. Bready served as CEO of Nabsys ...
(Date:3/21/2016)... 2016 Unique technology combines ... superior security   Xura, Inc. ... secure digital communications services, today announced it is working ... enterprise customers, particularly those in the Financial Services Sector, ... authentication within a mobile app, alongside, and in combination ...
(Date:3/14/2016)... 2016 NXTD ) ("NXT-ID" or the ... announces the airing of a new series of commercials on ... March 21 st .  The commercials will air on Bloomberg ... on the Street show. --> NXTD ) ("NXT-ID" ... commerce market, announces the airing of a new series of ...
Breaking Biology News(10 mins):