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:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
(Date:6/23/2016)... HOUSTON , June 23, 2016 ... agreement with the Cy-Fair Sports Association to serve ... of the agreement, Houston Methodist Willowbrook will provide ... education and connectivity with association coaches, volunteers, athletes ... partner with the Cy-Fair Sports Association and to ...
(Date:6/23/2016)... -- The Prostate Cancer Foundation (PCF) is pleased to announce 24 new ... prostate cancer. Members of the Class of 2016 were selected from a pool ... Read More About the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... --  EpiBiome , a precision microbiome engineering company, today ... from Silicon Valley Bank (SVB). The financing will allow ... drug development efforts, as well as purchase additional lab ... been an incredible strategic partner to us – one ... provide," said Dr. Aeron Tynes Hammack , EpiBiome,s ...
Breaking Biology Technology:
(Date:6/16/2016)... SAN FRANCISCO , June 16, 2016 /PRNewswire/ ... Market size is expected to reach USD ... report by Grand View Research, Inc. Technological proliferation ... and banking applications are expected to drive the ... ) , The development of ...
(Date:6/3/2016)... 2016 Das DOTM ... Nepal hat ein 44 Millionen ... Kennzeichen, einschließlich Personalisierung, Registrierung und IT-Infrastruktur, an ... und Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte internationale ... teilgenommen, aber Decatur wurde als konformste und ...
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of the medical ... premium product recently added to the range of products distributed by Ampronix. ... ... ... Ampronix News ...
Breaking Biology News(10 mins):