First Teleportation of Multiple Quantum Properties of a Single Photon

KentuckyFC writes Photons have many properties, such as their frequency, momentum, spin and orbital angular momentum. But when it comes to quantum teleportation, physicists have only ever been able to to transmit one of these properties at a time. So the possibility of teleporting a complete quantum object has always seemed a distant dream. Now a team of Chinese physicists has worked out how to teleport more than one quantum property. The team has demonstrated it by teleporting both the spin and orbital angular momentum of single photons simultaneously. They point out that there is no reason in principle why the technique cannot be generalized to include other properties as well, such as a photon's frequency, momentum and so on. That's an important step towards teleporting complex quantum objects in their entirety, such as atoms, molecules and perhaps even small viruses.

Comments

Re:not "quantum" not "teleportation"

[radtea]

this research is not what it purports to be...it's not like a "transporter" in Star Trek at all

TFS was actually doing pretty well until the last few sentences. What is being "telepored" are "quantum properties", which are nothing at all like classical properties and which are certainly unrelated to "objects".

The process is "quantum" in the sense that the information is hidden behind the quantum veil of the carrier wave. There is more to quantum phenomena than non-locality, although non-locality is one of the more spectacular ways it manifests.

Quantum "teleportation" happens to properties. Imagine you have a house of indeterminate colour, and a "colour teleporter" that consists of a beam of light between your house and another house a few miles away that will carry that colour of that house to your house. You turn the "teleporter" on, wait for the beam of light to establish itself, your confederate at the other end aims the "teleporter" at the first house, and your house becomes the colour of the first house at a time L/c later, where L is the distance the light has to travel and c is a well known constant.

This is a pretty close analogy to what is happening during "quantum teleportation"--and remember, if you stick you hand in the space the information is being "teleported" through you will get a hole burned in it by the perfectly ordinary laser beam that is used to carrying the information.

To leap from this "colour teleoportation" to the claim that "scientists teleported a house from one neighbourhood to the next" would be clearly and egregiously false, yet that is what discussions of quantum "teleportation" always end up with: people talking as if photons, atoms, molecules and viruses are being carried through space and reconstructed at the other end.

To see how wrong this is, consider a case where there is actual teleportation vs quantum "teleportation" of an electron to the Moon. In the case of actual teleportation, an important quantum number changes: the count of electrons on the Moon. In the case of quantum "teleportation" the Moon's electron number stays exactly the same. So the two final quantum states are completely different in these two cases. The processes have nothing to do with each other and it is misleading and wrong to talk about them as if they do.