Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stroboscope for Quantum Physicists: Resonator delivers short light pulses for entanglement

01.02.2010
An important milestone towards the construction of a quantum computer is the generation and investigation of large quantum systems. To this end, photons - the particles of light - are promising candidates.

Physicists of the group of Prof. Harald Weinfurter (at the Ludwig-Maximilians-Universität München and the Max-Planck-Institute for Quantum Optics, Garching, Germany, in the Cluster of Excellence "Munich Center for Advanced Photonics") succeeded in developing a new method for the generation of intense, ultra-short light pulses in the ultraviolet (UV) wavelength region at high repetition rates. These pulses are essential for the generation of multiple entangled photons.

The goal of the Munich scientists is to entangle as many photons as possible and to study their properties. Entanglement, or Einstein's "spooky action at a distance", still fascinates quantum physicists today. Therefore, their focus is not only on realizing the quantum computer, but they would also like to obtain a deeper insight into the world of quantum physics and to understand how entanglement is distributed over large quantum systems. To generate several entangled photons at once, ultra-short stroboscope-like light pulses of very high power are required. The main challenge for this project was to obtain ultra-short, high energy pulses with a high repetition rate and at UV wavelengths. All these demands had to be fulfilled at the same time.

The Munich team has now succeeded in transferring a method working in the infrared wavelength region to the more powerful ultraviolet region. They implemented a resonator to enhance UV light pulses with a pulse duration in the femtosecond regime (10-15 seconds) at a high repetition rate (82 MHz). Inside the resonator the pulses continuously add up only if the following condition is fulfilled: each incoming pulse has to overlap exactly with the pulses already stored in the resonator. The light intensity created in the resonator exceeds those of comparable commercial laser systems by at least a factor of five. A crystal inside the resonator then allows the generation of entangled photons.

Roland Krischek, who co-constructed and characterized the light resonator, sees a lot of potential: "This light resonator allows us to study entanglement of larger quantum systems." His colleague Witlef Wieczorek remarks: "This resonator can not only be used to generate multi-photon entanglement but also to analyze, for example, molecular formation or carrier dynamics in semiconductors."

The results of the Munich team are published in the next issue of Nature Photonics, online on January 31, 2010.

DOI: 10.1038/NPHOTON.2009.286

Christine Kortenbruck | idw
Further information:
http://www.munich-photonics.de
http://xqp.physik.uni-muenchen.de/

More articles from Physics and Astronomy:

nachricht The surprising environment of an enigmatic neutron star
18.09.2018 | Penn State

nachricht 'Optical rocket' created with intense laser light
17.09.2018 | University of Nebraska-Lincoln

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: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

Im Focus: Graphene enables clock rates in the terahertz range

Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.

Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

 
Latest News

World's first passive anti-frosting surface fights ice with ice

18.09.2018 | Materials Sciences

A novel approach of improving battery performance

18.09.2018 | Materials Sciences

Scientists use artificial neural networks to predict new stable materials

18.09.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>