Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Toronto physicists take quantum leap toward ultra-precise measurement

03.06.2014

For the first time, physicists at the University of Toronto (U of T) have overcome a major challenge in the science of measurement using quantum mechanics. Their work paves the way for great advances in using quantum states to enable the next generation of ultra-precise measurement technologies.

"We've been able to conduct measurements using photons – individual particles of light – at a resolution unattainable according to classical physics," says Lee Rozema, a Ph.D. candidate in Professor Aephraim Steinberg's quantum optics research group in U of T's Department of Physics, and one of the lead authors along with M.Sc. candidate James Bateman of a report on the discovery published online today in Physical Review Letters. "This work opens up a path for using entangled states of light to carry out ultra-precise measurements."


University of Toronto physics students James Bateman (left) and Lee Rozema (right) led a study which successfully measured multiple photons in an entangled NOON state. The work paves the way for great advances in using quantum states to enable the next generation of ultra-precise measurement technologies.

Credit: Diana Tyszko

Many of the most sensitive measurement techniques in existence, from ultra-precise atomic clocks to the world's largest telescopes, rely on detecting interference between waves – which occurs, for example, when two or more beams of light collide in the same space. Manipulating interference by producing photons in a special quantum state known as an "entangled" state – the sort of state famously dismissed by a skeptical Albert Einstein as implying "spooky action at a distance" – provided the result Rozema and his colleagues were looking for. The entangled state they used contains N photons which are all guaranteed to take the same path in an interferometer – either all N take the left-hand path or all N take the right-hand path, but no photons leave the pack.

The effects of interference are measured in devices known as "interferometers." It is well known that the resolution of such a device can be improved by sending more photons through it – when classical light beams are used, increasing the number of photons (the intensity of the light) by a factor of 100 can improve the resolution of an interferometer by a factor of 10. However, if the photons are prepared in a quantum-entangled state, an increase by a factor of 100 should improve the resolution by that same full factor of 100.

The scientific community already knew resolution could be improved by using entangled photons. Once scientists figured out how to entangle multiple photons the theory was proved correct but only up to a point. As the number of entangled photons rose, the odds of all photons reaching the same detector and at the same time became astronomically small, rendering the technique useless in practice.

So Rozema and his colleagues developed a way to employ multiple detectors in order to measure photons in entangled states. They designed an experimental apparatus that uses a "fibre ribbon" to collect photons and send them to an array of 11 single-photon detectors.

"This allowed us to capture nearly all of the multi-photons originally sent," says Rozema. "Sending single photons as well as two, three and four entangled photons at a time into our device produced dramatically improved resolution."

The U of T experiment built on a proposal by National University of Singapore physicist Mankei Tsang. In 2009, Tsang posited the idea of placing detectors at every possible position a photon could reach so that every possible event could be recorded, whether or not multiple photons hit the same detector. This would enable the calculation of the average position of all the detected photons, and could be done without having to discard any of them. The theory was quickly tested with two photons and two detectors by University of Ottawa physicist Robert Boyd.

"While two photons are better than one, we've shown that 11 detectors are far better than two," says Steinberg, summarising their advancement on Boyd's results. "As technology progresses, using high-efficiency detector arrays and on-demand entangled-photons sources, our techniques could be used to measure increasingly higher numbers of photons with higher resolution."

The discovery is reported in a study titled "Scalable spatial superresolution using entangled photons" published in the June 6 issue of Physical Review Letters. It is recommended as an Editor's Suggestion, and is accompanied by a commentary in the journal Physics which describes the work as a viable approach to efficiently observing superresolved spatial interference fringes that could improve the precision of imaging and lithography systems.

###

In addition to Steinberg, Rozema and Bateman's collaborators on the research included Dylan Mahler, Ryo Okamoto of Hokkaido and Osaka Universities, Amir Feizpour, and Alex Hayat, now at the Technion - Israel Institute of Technology. Support for the research was provided by the Natural Sciences and Engineering Research Council of Canada and the Canadian Institute for Advanced Research, as well as the Yamada Science Foundation.

MEDIA CONTACTS:

Lee Rozema
Department of Physics
University of Toronto
lrozema@physics.utoronto.ca
416-946-3162

Aephraim Steinberg
Department of Physics
University of Toronto
steinberg@physics.utoronto.ca
416-978-0713

Sean Bettam
Communications, Faculty of Arts & Science
University of Toronto
s.bettam@utoronto.ca
416-946-7950

Sean Bettam | Eurek Alert!
Further information:
http://www.utoronto.ca

Further reports about: Physics detector detectors measurement measurements photons spatial techniques

More articles from Physics and Astronomy:

nachricht Artificial Intelligence Helps in the Discovery of New Materials
21.09.2016 | Universität Basel

nachricht Magnetic polaron imaged for the first time
19.09.2016 | Aalto University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>