A Quantum Memory Storage Prototype

eldavojohn writes "An Australian National University project has completed a proof-of-concept storage unit that relies on bringing light to a standstill inside a crystal and then releasing it later for a read-once storage device. There are a few complexities to work out, such as the -270 degrees Celsius requirement to stop the light. And there is an interesting side effect noted by the team lead: 'We could entangle the quantum state of two memories, that is, two crystals. According to quantum mechanics, reading out one memory will instantly alter what is stored in the other, no matter how large the distance between them. According to relativity, the way time passes for one memory is affected by how it moves. With a good quantum memory, an experiment to measure how these fundamental effects interact could be as simple as putting one crystal in the back of my car and going for a drive.' Hopefully this will lead to a better understanding and simple testing of quantum entanglement."

Re:Quantum communication?

[mathfeel]

One cannot transfer information with a fundamentally probabilistic process.

Re:Quantum communication?

[Burnhard]

What do you mean by "simulation"? Simulating what? A real Universe? Which real Universe? And why isn't that real Universe this one, rather than this one being a simulation of a real Universe? The idea that it's a simulation is really the same as saying, "God does it".

Re:Quantum communication?

[Burnhard]

No, they don't. They are what they are only in the context of our limited understanding and the inherent limitations of the tools we have for exploring the nature of the Universe (mathematics). Explaining it as a computer simulation brings nothing to the table in terms of knowledge. It just moves the problem one step further away (as invoking a God would), requiring an even greater more complex entity that itself has to be explained.

Re:Quantum Entanglement does not "transfer" anythi

[ZDRuX]

I'm no physicist so pardon my ignorance but maybe you can help explain. Are we able to change the state of one of these particles at will? And if we are, does the other entangled particle change states as well?

If the two particles simply exhibit a mirror-like effect but we have no way of changing their state, then I agree that this is quite useless at this stage. However, if we are able to change the state of one particle and the other changes as well, then we can have data-transfer (think 1s and 0s, ON and OFF) across limitless distances.

Military would salivate over this a communication channel that cannot be interrupted through regular means like rock and walls, yet is absolutely un-tappable no matter where you are in the universe.

Re:Quantum Entanglement does not "transfer" anythi

[Your.Master]

However, if we are able to change the state of one particle and the other changes as well, then we can have data-transfer (think 1s and 0s, ON and OFF) across limitless distances.

You have hidden assumptions here. We are able to change the state at will, but we are not able to choose what state we change it to, and it's a one-time operation. All you can "communicate" is entirely random data -- which is very useful for quantum cryptography when combined with a classical communications channel, but doesn't have many other evident uses.

Re:Serious question: Faster than light communicati

[Urkki]

One thing I always wondered:

Let's say I have a total of 1024 entangled pairs; well contained and stable. Now, I take the one half of those pairs and transport them somewhere else. Then, I proceed to measure the state of them _or not_. When checking the other half, shouldn't I get a total of 1024 "altered" and "unaltered" read-outs, resulting in the transmission of 128 bytes?

You can't measure if a particle is entangled, or if something was done to the entangled pair even if you know it's entangled.

So no transferring information that way, sorry.