Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

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

Physics

Could black phosphorus be the next silicon? New material could make it possible to pack more transistors on a chip, research suggests July 7th, 2015

Superconductor could be realized in a broken Lorenz invariant theory July 7th, 2015

Crystal structure and magnetism -- new insight into the fundamentals of solid state physics: HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically 'frustrated' spinel system July 7th, 2015

News and information

Superconductor could be realized in a broken Lorenz invariant theory July 7th, 2015

New technique enables magnetic patterns to be mapped in 3-D July 7th, 2015

Crystal structure and magnetism -- new insight into the fundamentals of solid state physics: HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically 'frustrated' spinel system July 7th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Could black phosphorus be the next silicon? New material could make it possible to pack more transistors on a chip, research suggests July 7th, 2015

A cool way to form 2-D conducting polymers using ice: POSTECH scientists develop breakthrough technique to easily optimize electrical properties of Polyaniline nanosheets to an unprecedented level in an environmental-friendly and inexpensive way July 7th, 2015

New technique enables magnetic patterns to be mapped in 3-D July 7th, 2015

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Discoveries

Superconductor could be realized in a broken Lorenz invariant theory July 7th, 2015

New technique enables magnetic patterns to be mapped in 3-D July 7th, 2015

Crystal structure and magnetism -- new insight into the fundamentals of solid state physics: HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically 'frustrated' spinel system July 7th, 2015

Down to the quantum dot: Jülich researchers develop ultrahigh-resolution 3-D microscopy technique for electric fields July 7th, 2015

Announcements

Superconductor could be realized in a broken Lorenz invariant theory July 7th, 2015

New technique enables magnetic patterns to be mapped in 3-D July 7th, 2015

Crystal structure and magnetism -- new insight into the fundamentals of solid state physics: HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically 'frustrated' spinel system July 7th, 2015

Down to the quantum dot: Jülich researchers develop ultrahigh-resolution 3-D microscopy technique for electric fields July 7th, 2015

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

Could black phosphorus be the next silicon? New material could make it possible to pack more transistors on a chip, research suggests July 7th, 2015

Superconductor could be realized in a broken Lorenz invariant theory July 7th, 2015

New technique enables magnetic patterns to be mapped in 3-D July 7th, 2015

Crystal structure and magnetism -- new insight into the fundamentals of solid state physics: HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically 'frustrated' spinel system July 7th, 2015

Photonics/Optics/Lasers

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Pioneering Southampton scientist awarded prestigious physics medal July 3rd, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Opening a new route to photonics Berkeley lab researchers find way to control light in densely packed nanowaveguides June 27th, 2015

Quantum nanoscience

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Freezing single atoms to absolute zero with microwaves brings quantum technology closer: Atoms frozen to absolute zero using microwaves July 2nd, 2015

The quantum spin Hall effect is a fundamental property of light June 25th, 2015

Lancaster University revolutionary quantum technology research receives funding boost June 22nd, 2015

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project