Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

2 crystals linked by quantum physics

05.03.2012
Researchers at the UNIGE have succeeded in entangling 2 macroscopic crystals, a step towards the development of quantum memory
For almost fifteen years Professor Nicolas Gisin and his physicist collaborators have been entangling photons. If this exercise seems to them perhaps henceforth trivial, it continues to elude us ordinary humans. The laws that govern the quantum world are so strange that they completely escape us human beings confronted with the laws of the macroscopic world. This apparent difference in nature between the infinitesimally small and our world poses the question of what link exists between the two.

However these two worlds do interact. To realise this, one must follow the latest experiment of the Group of Applied Physics (GAP). Nicolas Gisin, researcher Mikael Afzelius and their team have actually produced the entanglement of two macroscopic crystals, visible to the naked eye, thanks to a quantum particle, a photon, otherwise known as a particle of light.

To achieve this exploit, the physicists developed a complex device to which they hold the key. After a first system that allows them to verify that they've actually managed to release one, and only one, photon, a condition essential to the success of the experiment, a second device "slices" this particle in two. This splitting allows the researchers to obtain two entangled photon halves. In other words, even though they are not in the same location, the two halves continue to behave as if they were one.

Wait for the photons to exit

The two halves are then each sent through a separate crystal where they will interact with the neodymium atoms present in its atomic structure. At that moment, because they are excited by these entangled photons, the neodymium lattices in each crystal likewise become entangled. But how can we be certain that they've actually reacted to the two photon halves?

That's simple ... or nearly! They just have to wait for the two particles to exit the crystals - since they exit after a rather brief period of about 33 nanoseconds - and to verify that it really is the entangled pair. "That's exactly what we found since the two photons that we captured exiting the crystals showed all the properties of two quantum particles behaving as one, characterised by their simultaneity in spite of their separation", Feìlix BussieÌres rejoices, one of the authors of the article.

In addition to its fundamental aspect, this experiment carries with it potential applications. Actually, for the specialists in quantum entanglement, this phenomenon has the unpleasant habit of fading when the two entangled quantum objects are too far from one another. This is problematic when one envisions impregnable quantum cryptography networks which could link two distant speakers separated by several hundreds or even thousands of kilometres.

"Thanks to the entanglement of crystals, we can now imagine inventing quantum repeaters", Nicolas Gisin explains, "in other words, the sorts of terminals that would allow us to relay entanglement over large distances. We could then also create memory for quantum computers."

Entanglement still has many surprises in store for us.

Nicolas Gisin | EurekAlert!
Further information:
http://www.unige.ch

More articles from Physics and Astronomy:

nachricht A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

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: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>