Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Detection of single photons via quantum entanglement

As a ‘quantum pendulum’ the ions swing in both directions at the same time. Illustration: IQOQI/Knabl
As a ‘quantum pendulum’ the ions swing in both directions at the same time.

Illustration: IQOQI/Knabl

Abstract:
Almost 200 years ago, Bavarian physicist Joseph von Fraunhofer discovered dark lines in the sun's spectrum. It was later discovered that these spectral lines can be used to infer the chemical composition and temperature of the sun's atmosphere. Today we are able to gain information about diverse objects through light measurements in a similar way. Because often very little light needs to be detected for this, physicists are looking for ever more sensitive spectroscopy methods. In extreme cases, also single particles of light (photons) need to be measured reliably, which is technically challenging.

Detection of single photons via quantum entanglement

Innsbruck, Austria | Posted on July 9th, 2013

Thus, physicists at the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences and the Institute for Experimental Physics of the University of Innsbruck take a detour via the technique of quantum logic spectroscopy. It was developed some years ago by the group of Nobel laureate David Wineland to build extremely precise atomic clocks. This is one of the first practical applications of quantum information processing and, in the next few years, may lead to a redefinition of the second in the international system of units.

Measurement via entanglement

Christian Roos' and Cornelius Hempel's team of physicists in Innsbruck isolated single ions in an ion trap to study them under controlled conditions. "We do not try to detect the photon that is emitted or absorbed by an ion, but rather the momentum kick the ion receives upon absorption or emission," explains Cornelius Hempel. "While this effect is extremely small, we can detect it by means of quantum physics." The physicists use an additional ‘logic' ion, on which the measurement is performed. "This calcium ion (40Ca+) can be controlled very well in the experiment," says Hempel. As spectroscopy ion the researchers use another isotope of calcium (44Ca+).

In the experiment a laser pulse excites the particles and entangles the electronic state of the logic ion with the vibration of the particles. "In this configuration, also called Schrödinger cat state, the ions swing like a classical pendulum in a trap. But as a ‘quantum pendulum' they swing in both directions at the same time," describes Hempel the central part of the experiment. "We then excite the ion we want to investigate by applying different laser frequencies. At a certain frequency the ion emits a single photon and receives a minimal momentum kick, which causes the vibrational components to be slightly displaced. This can be observed through the electronic state of the logic ion. Combined with this information, the frequency of the laser then allows us to gain information about the internal state of the spectroscopy ion." In the current experiment the scientists detected single photons with a probability of 12 %. "We, thus, prove that this technique works in principal. With a technically optimized set-up we will be able to considerably increase the sensitivity," say Roos and Hempel confidently.

Universal application

"By using the exotic concept of quantum mechanical entanglement we are able to gain practical knowledge about single particles," says Christian Roos excitedly. "Since our method of measurement does not depend that much on the wave length of the detected photon, it may be used for various purposes," adds Cornelius Hempel. For example, energy levels of different atoms and molecules could be investigated by using this technique. Because it is difficult to control molecules in an experiment, this method is an enormous progress for studying more complex structures.

This research, carried out at the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences and at the Institute for Experimental Physics at Innsbruck University, was supported by the European Union.


Full bibliographic information

Entanglement-enhanced detection of single-photon scattering events. C. Hempel, B. P. Lanyon, P. Jurcevic, R. Gerritsma, R. Blatt, C. F. Roos. Advance online publication. Nature Photonics 2013
DOI: 10.1038/nphoton.2013.172

####

About University of Innsbruck
The University of Innsbruck was founded in 1669 and is one of Austria's oldest universities. Today, with almost 3,500 staff and 23,000 students, it is a place of learning that unifies tradition with future, progress and the joy of discovery. The University of Innsbruck is western Austria's largest institution of higher education and research and serves as major university for the regions of Tyrol, Vorarlberg and South Tyrol and the state of Liechtenstein. At their 15 faculties, scientist are researching and teaching in the various fields of Arts and Letters, Law, Social Sciences and Economics, Catholic Theology, Natural Sciences, Civil Engineering and Architecture.

For more information, please click here

Contacts:
Cornelius Hempel
Institute for Quantum Optics and Quantum Information
Austrian Academy of Sciences
+43 512 507 4722

Copyright © AlphaGalileo

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

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Physics

How a tetrahedral substance can be more symmetrical than a spherical atom: A new type of symmetry September 14th, 2018

Ultracold atoms used to verify 1963 prediction about 1D electrons: Rice University, University of Geneva study focuses on theory that's increasingly relevant to chipmakers September 5th, 2018

Energy-efficient spin current can be controlled by magnetic field and temperature: SCMR effect simplifies the design of fundamental spintronic components August 20th, 2018

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Could a demon help to create a quantum computer? Physicists implement a version of Maxwell's famous thought experiment for reducing entropy September 5th, 2018

Discoveries

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Announcements

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

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

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

New devices based on rust could reduce excess heat in computers: Physicists explore long-distance information transmission in antiferromagnetic iron oxide September 14th, 2018

Photonics/Optics/Lasers

Halas wins American Chemical Society Award in Colloid Chemistry: Rice University nanophotonics pioneer honored for colloid research September 18th, 2018

Tiny camera lens may help link quantum computers to network September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Laser sintering optimized for printed electronics: New study sheds (laser) light on the best means of laying down thin-film circuitry September 13th, 2018

Quantum nanoscience

September 5th, 2018

A Novel Graphene Quantum Dot Structure Takes the Cake August 24th, 2018

How hot is Schrödinger's coffee? August 15th, 2018

Breaking down the Wiedemann-Franz law: In a study exploring the coupling between heat and particle currents in a gas of strongly interacting atoms, physicists at ETH Zurich find puzzling behaviours August 10th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project