What sort of wild technology do you need to entangle particles?

May 28, 2012 1:49 PM

I need to know what sort of equipment one uses to "entangle" particles. Where would I find this sort of information?

I've been playing around with a story idea (possibly extendable into novel form) that involves some of the odder stuff that people have been doing with entangled particles (quantum information teleportation, and more specifically, Masahiro Hotta's quantum energy teleportation). I'm trying for realism, as much as is possible, and I'm running into a problem - I have no idea what sort of equipment would be used for something like this.

Does entangling two particles involve CERN-level high-energy physics? Careful isolation from all outside influences? I've been able to track down a lot of stuff about what entanglement is on Wikipedia and the Internet at large, but aside from a few lab pictures, there's not much about the actual devices and procedures involved.

posted by AdamCSnider to Technology (4 answers total)

Best answer: Certainly not CERN-scale. The particles used in current entanglement experiments are photons of laser light. Such experiments are constructed on a special tabletop designed for building optical systems. You just need a laser about the size of a toaster, some mirrors and beamsplitters, bits of crystal in special mounts, and so on. This isn't quite my field so I'm not totally certain, but I would guess that if you wanted to commercialize an entangled-photon source you could do so in a box the size of a bar fridge or less.

Here are some pictures that show the entirety of current a experimental setup being moved, which give a good idea of the scale and appearance of such things.
posted by Pre-Taped Call In Show at 4:28 PM on May 28, 2012

Oh, as for isolation from outside influences: Optics tables sit on legs which isolate them from the vibrations of the floor but all of the actual components are just sitting in the air; care must often be taken to control the ambient temperature and minimize air currents and turbulence, dust is bad, and some components need to be cleaned from time to time. That's about it. A sealed box would solve most of these problems.
posted by Pre-Taped Call In Show at 4:43 PM on May 28, 2012

There are a lot of different things that can be entangled. You can have entangled photons, entangled electrons, entangled ions, entangled atoms... Experiments vary. But yes, a laser is the standard way to "talk to" a particle, so yes, a laser will be involved. Often it'll be a pulsed laser, since that's the best way to raise the peak intensity of the light, and those tend to be more suitcase-sized than toaster-sized, but it varies. The laser is pointed at some kind of target. If you read an article and it talks about an atomic beam, or just refers to "atoms" without saying what the medium is, then there's a vacuum chamber involved - but that's something about the size of an old-fashioned metal diving helmet. Such a setup could be built in a space the size of a one-car garage, but two-car would be more comfortable.
posted by aimedwander at 6:52 AM on May 29, 2012

But when building a 'machine', there's a lot of scope for miniaturization compared to the setups typically seen in university research labs. If you are putting together an experiment from scratch for the first time (from parts out of the thorlabs catalogue or whatever), you need ease of access to modify and manipulate the components, and to make it simple to reconfigure the entire setup when you want to move on to a different experiment. You also use far larger components than are strictly necessary, to make it easier to set up and align.
posted by Pre-Taped Call In Show at 7:31 AM on May 29, 2012