Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Heidelberg Researchers Create “Squeezed” Quantum Vacuum Filled with Atoms

02.12.2011
Based on a new detection method to access previously unobtainable measurements in atomic gases

Quantum theory is known for its peculiar concepts that appear to contradict the fundamental principles of traditional physics. Researchers from Heidelberg University have now succeeded in creating a special quantum state between two mesoscopic gases with approximately 500 atoms.


Typically noise is unwanted in experiments, and the challenge is minimising it. In the experiment of generating and detecting a „squeezed“ vacuum, the noise is the signal that reveals the existence of quantum entanglement. Even though the number of atoms in both gases (marked in red and blue) fluctuates extremely, their difference (marked in black) is very small. In order to obtain a correct analysis, a few experiments (on the left) are not sufficient. The noise has to be analysed in long series of measurements (on the right). Figure: Kirchhoff Institute for Physics

The state is known as a “squeezed“ vacuum, in which measuring one gas affects the results of the measurement on the other. To produce these results the team, headed by Prof. Dr. Markus Oberthaler at the Kirchhoff Institute for Physics, had to develop a novel detection technique to measure values in atomic gases that were previously unobtainable. The results of their research have been published in the journal “Nature”.

The quantum state observed by the Heidelberg researchers has been of fundamental interest since it was first put forward in 1935 by Einstein, Podolsky and Rosen (EPR) in a thought experiment. The three researchers wanted to use it to demonstrate that quantum mechanics is not consistent with a local reality of physical systems that is experimentally observable. The EPR situation refers to two systems in a state of quantum entanglement, where measuring one system instantaneously effects the results of the measurement on the other – an incomprehensible fact to our traditional way of thinking, where physical laws exist regardless of whether systems are observed or not.

The breakthrough in the quantum state discovered and created by Prof. Oberthaler and his team lies in the quantum entanglement of continuous variables. This means that in principle, individual measurements of the two gases randomly produce many different values. After measuring one gas, however, all the other measurements on the second – entangled – gas can be precisely predicted. To create and detect a “squeezed” quantum vacuum with its unique characteristics in the laboratory, the researchers worked with a Bose Einstein condensate. This condensate is an extreme aggregate state of a system of indistinguishable particles, most of which are in the same quantum mechanical state. The condensate used was comprised of Rubidium atoms cooled to an ultracold temperature of 0.000 000 1 Kelvin above absolute zero.

“The setup of the experiment had to be extraordinarily stable since we took measurements continuously for many days in a row to gather enough data to verify the generation of a quantum entanglement”, explains Prof. Oberthaler. For this purpose, the researchers had to guarantee the stability of magnetic fields that is 10,000 times smaller than of the magnetic field of the earth. They also needed to detect a gas consisting of 500 atoms with an error tolerance of less than eight atoms since the particle number fluctuations served as the signal for a successful generation of an entanglement. Prof. Oberthaler: “Normally you don’t want noise in experiments, but in our investigations careful examination of the noise actually proved the presence of the quantum entanglement.” The challenge for the Heidelberg team was suppressing the technical noise enough to allow the quantum noise to dominate.

Prof. Oberthaler and his colleagues hope not only that their research results lead to an application for precise atomic interferometry, but also see their findings as an important step in the investigation of fundamental questions of quantum mechanical entanglement of massive particles.

For information online, see http://www.kip.uni-heidelberg.de/matterwaveoptics.

Original publication:
C. Gross, H. Strobel, E. Nicklas, T. Zibold, N. Bar-Gill, G. Kurizki and M.K. Oberthaler: Atomic homodyne detection of continuous-variable entangled twin-atom states. Nature online, 30 November 2011, doi: 10.1038/nature10654
Contact:
Prof. Dr. Markus Oberthaler
Kirchhoff Institute for Physics
Phone: +49 6221 54-5170
markus.oberthaler@kip.uni-heidelberg.de
Communications and Marketing
Press Office, phone: +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.kip.uni-heidelberg.de/matterwaveoptics

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>