Physicists use lasers to entangle diamonds

[DainBramaged]

Quantum entanglement(⇣?) is probably the most confusing and confused concept in quantum mechanics. Normally, two particles can be described using separate mathematical descriptions. But, under certain circumstances, they can become mixed in such away that only a single mathematical description can accurately predict their behavior. The consequence is that these two particles, even when separated by vast amounts of space, are linked—measurements on one particle will reveal information about the other.

Entanglement is very, very delicate. As a particle bounces off of other particles, its properties are modified in an unpredictable way, which shows up as the loss of our ability to predict both the particle's behavior and that of its partner. So, entanglement is typically found in very clean systems, where particles don't interact too much. It came as something of a surprise to find a paper describing entanglement of phonons—sound waves in crystals. This implies that the mechanical motion of some 1016 atoms was entangled, which is an impressive feat.

Why call a sound wave a phonon?
In a normal crystal, the atoms are arranged in a regular structure. If you stop somewhere in a crystal and take a picture, then if you move a particular distance and take a second picture, the two pictures will match up exactly. This regular structure introduces a periodicity to the frequencies of sound waves that travel through the crystal. This is because sound waves involve the mechanical motion of the atom.

So, imagine that we freeze a sound wave in a crystal and take a look at where the atoms are. One atom happens to sit on a point where the sound wave has shifted it as far as possible from its normal location (called an anti-node). If we travel along the frozen sound wave, we will find another atom that is also at an anti-node. That atom has to occupy the same position in the crystal lattice as the first atom.

http://arstechnica.com/science/news/2011/12/physicists-use-lasers-to-entangle-diamonds.ars#entry/49540

[hermetic]

1. Just goes to show,

We are all ONE.

[dtexdem]

2. Wow, I knew that diamonds were forever -- now they can talk to one another from across the universe.

;-)