Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new approach to on-chip quantum computing

02.10.2014

New low-power method opens the door for easily fabricating future quantum communication and computing devices

Commercial devices capable of encrypting information in unbreakable codes exist today, thanks to recent quantum optics advances, especially the generation of photon pairs—tiny entangled particles of light.


Cross-polarized pump photons (red and blue) interact in the micro-ring resonator to directly generate cross-polarized correlated photons (green and yellow).

Credit: Lucia Caspani

Now, an international team of researchers led by professor Roberto Morandotti of INRS-EMT in Canada, is introducing a new method to achieve a different type of photon pair source that fits into the tiny space of a computer chip.

The team's method, which generates "mixed up" photon pairs from devices that are less than one square millimeter in area, could form the core of the next-generation of quantum optical communication and computing technology. The research will be presented at The Optical Society's (OSA) 98th Annual Meeting, Frontiers in Optics, being held Oct. 19-23 in Tucson, Arizona, USA.

One of the properties of light exploited within quantum optics is "photon polarization," which is essentially the direction in which the electric field associated with the photon oscillates. The research team set out to find a way to directly "mix up," or cross-polarize, the photons via a nonlinear optical process on a chip.

"While several efforts have been devoted to develop on-chip sources of polarization-entangled photons, the process typically used to generate these photons only allows the generation of photons with the same polarization as the laser beam used to pump the device — either both horizontal or vertical — after which entanglement can be achieved by accurately mixing these states. Now, we have found a way to directly generate cross-polarized photon pairs," says Lucia Caspani, a postdoctoral fellow at INRS-EMT and co-author of the Frontiers in Optics paper.

To generate the cross-polarized photons, Caspani and colleagues used two different laser beams at different wavelengths —one vertically polarized and another horizontally polarized. The approach, however, came with a potential pitfall: the classical process between the two pump beams could destroy the photons' fragile quantum state.

To address this challenge, the team, which also includes researchers from RMIT University in Australia and City University of Hong Kong, pioneered a new approach based on a micro-ring resonator—a tiny optical cavity with a diameter on the order of tens to hundreds of micrometers—that operates in such a way that energy conservation constraints suppress classical effects while amplifying quantum processes.

While a similar suppression of classical effects has been observed in gas vapors and complex micro-structured fibers, this is the first time it has been reported on a chip, thus opening a clear route for building scalable integrated devices.

"Our approach opens the door to directly mixing different polarizations on a chip," Caspani points out. "At very low power, our device directly generates photon pairs with orthogonal polarizations, which can be exploited for quantum communication and computing protocols."

The fabrication process of the chip is also compatible with that currently used for electronic chips. "It enables a future coexistence of our device with standard integrated circuits," says Caspani, which is a fundamental requirement for the widespread adoption of optical quantum technologies.

Presentation FTu2A.2, "Direct Generation of Orthogonally Polarized Photon Pairs via Spontaneous Non-Degenerate FWM on a Chip," takes place Tuesday, Oct. 21 at 11 a.m. MST at the Arizona Ballroom, Salon 8 at the JW Marriott Tucson Starr Pass Resort in Tucson.

PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Marriott, Sunday through Thursday, Oct. 19-23. Those interested in obtaining a press badge for FiO should contact OSA's Lyndsay Meyer at 202.416.1435 or lmeyer@osa.org.

About FiO/LS

Frontiers in Optics (FiO) 2014 is The Optical Society's (OSA) 98th Annual Meeting and is being held together with Laser Science, the 30th annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at http://www.FrontiersinOptics.org.

Lyndsay Meyer | Eurek Alert!

Further reports about: APS FiO Laser OSA Optical optics photon pairs photons polarization quantum computing quantum optics

More articles from Physics and Astronomy:

nachricht Black hole spin cranks-up radio volume
15.01.2018 | National Institutes of Natural Sciences

nachricht The universe up close
15.01.2018 | Georg-August-Universität Göttingen

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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Morbid Obesity: Gastric Bypass and Sleeve Gastrectomy Are Comparable

17.01.2018 | Health and Medicine

Researchers identify new way to unmask melanoma cells to the immune system

17.01.2018 | Health and Medicine

Genetic discovery may help better identify children at risk for type 1 diabetes

17.01.2018 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>