Ames Computers / Walden Systems

     European research groups have managed to entangle separated clouds of thousands of atoms, not just a pair of particles. They've also found a way to harness their technological potential. The quantum world of atoms and particles is strange, unpredictable and predictable at the same time. The strange properties of quantum mechanics are not mathematical quirks, they are real effects that have been seen in laboratories repeatedly. One of the features of quantum mechanics is entanglement, particles that are mysteriously linked regardless of how far away from each other they are. When particles are entangled they share properties in a way that makes them dependent on each other, even when they are separated by large distances. Einstein called this entanglement phenomenon a "spooky action at a distance," as altering one particle in an entangled pair affects its twin instantaneously, no matter how far away it is. While entanglement may seem bizarre, experiments have been able to show that it exists for many years now. It also has the potential to be useful to transfer a particle's quantum state, such as spin, from one location to another immediately as in teleportation. They can also help store a huge amount of information in a given volume. Besides it's storage potential, entanglement can help link and combine the computing power of systems in different locations all over the world. Another potential is secure communications, since any attempt to interfere with systems involving entangled particles immediately disrupts the entanglement, making it obvious that a message has been altered. Entangled photons also have tbe potential to enhance the resolution of imaging techniques. University of Waterloo researchers are hoping to develop a quantum radar that may be capable of detecting stealth aircraft.

     Real world applications using technologies based on the entanglement property is proving to be a daunting task. The reason for this is that entanglement is a very fragile phenomenon. Experiments on entanglement typically produce individual pairs of particles. However, single particles are difficult to detect accurately and they are often lost or obscured by background noise. So the task of producing them in entangled states, manipulating them in the ways required for useful operations, and finally using them, is often daunting. This is where the new research has made a significant breakthrough, instead of taking single particle and entangling them one at a time, the researchers began with an ultra cold gas that consists of thousands of atoms. These are cooled to near absolute zero, the lowest temperature possible. The researchers showed that you can split these clouds into groups and still preserve the quantum connection between the atoms inside. They did this by releasing the atoms from their confined space and using a laser to split it and measure the properties of distant parts of the expanded cloud. When confined in a small area, atoms in such a cloud become indistinguishable from each other, forming a new state of matter known as a Bose-Einstein condensate. The atoms in the cloud now behave collectively; they are entangled. Scientists first discovered this state of matter in 1995, which won Nobel prize in physics in 2001. Even though it has been known for some time that this method entangles thousands of atoms simultaneously, no one had demonstrated a technique to actually make use of it, until now.