Chip atomic generates pairs of atoms twins

The chip emits atomic atoms quantum-mechanically correlated, useful in computing and quantum cryptography and teleportation. [Image: TUWien] 

Entangled particles 

In the classical world, when something explodes, the particles forming this thing spread out in all directions.

Each particle has its own characteristics, sharing with the thousands, or millions, of other particles born from the explosion, little more than the story of a common origin.

In the quantum world, however, things are more subtle: it is possible to generate particles from a common source that will be exact duplicates of one another.

These so-called entangled particles have everything in common, and can not even be understood separately - they are quantum-mechanically linked, and only differ from each other by the direction of their movement.

Interlacement



Not even Einstein liked the idea of two separate particles remain entangled by the laws of quantum mechanics - he called the phenomenon of spooky action at a distance.

Weird or not, the fact is that the phenomenon has been confirmed by numerous experiments, and is one of the most promising tools for quantum computing to quantum cryptography and teleportation.

"This does not mean that by manipulating a particle, we can simultaneously change the other, as if they were connected by an invisible thread, but still have to treat the two particles as a single quantum system," explains Dr. Jörg Schmiedmayer, Technical University of Vienna.

But it means that measuring one of them, the simple process of measurement will also collapse the wave function of the other. This has enormous interest for the data processing and transfer of optical information.

Atomic Chip



So far, the greatest difficulty to experiment with these entangled particles was producing the very phenomenon of entanglement, ie, produce particles linked in a consistent and reliable.

It was this problem that Dr. Schmiedmayer and his colleagues have now solved: they created what they call 'atomic chip', a generator that produces entangled pairs of atoms correlated.

The 'atomic chip' is the main element with a Bose-Einstein condensate, an exotic state of matter in which millions of ultra-cold atoms, all in their energy level as low as possible, behave like a single atom.

To make your function generator entangled atoms, scientists can shoot the smallest unit of vibrational energy into the condensate.

After receiving the vibration of the atoms must return to their state of lowest energy. For this, the condensate must release the extra energy received.

"Due to the sophisticated design of the chip atom, the Bose-Einstein gets only one way to release their energy: sending pairs of atoms. All other possibilities are forbidden by quantum mechanics," explains Robert Bucker, co-author of the work .

Schematic of the excitation and emission of atoms intertwined. The central part of the system shows the spatial structure of radially excited state. Are emitted clouds containing two atoms twins. [Image: Bucker et al. / Nature]

Entangled atoms



According to the law of conservation of momentum, the two atoms move in exactly opposite directions. This process is very similar to what occurs in certain optical crystals, in which one can create pairs of photons.

Now, however, the atomic chip, scientists can have massive particles intertwined, rather than light.

The two entangled atoms form a single quantum object. One can not be described mathematically describe it without the other also.

"We are preparing to use these atoms for new experiments incredible," enthuses Schmiedmayer. "They are opening a new field of research, which will evolve new insights and possibly new applications. "

According to the researcher, it is difficult to predict the impact of the generator of entangled atoms. Conceptually, however, it is possible to devise new techniques for quantum measurements with a precision far superior to that obtained by classical physics.