Live data from Hacker News

Two Big Steps Toward the Quantum Computer

popularmechanics.com

11–20 of 35 posts

Re: Two Big Steps Toward the Quantum Computer

#11

When two network quantum chips can communicate instantly (not at speed of light--instantly) over infinite distances, using entangled atoms, then we can ditch the tecos. I'm so looking forward to that.

Faster-than-light communication using entanglement is not possible, according to the standard rules of quantum mechanics.

(Dropping some credentials doesn't seem inappropriate here: I worked professionally as a researcher on quantum computing and quantum information for 13 years.)

Re: Two Big Steps Toward the Quantum Computer

#12
post #7

When two network quantum chips can communicate instantly (not at speed of light--instantly) over infinite distances, using entangled atoms, then we can ditch the tecos. I'm so looking forward to that.

how would you entangle the photons in the first place? from what i understand they have to be in close proximity or even emitted from the same source. once entangled, they need to be maintained in this state very very carefully. i think a few hours is the record currently. to really reap the benefits of entanglement for anything other than microsecond HFT algos, like for human telecommunication, you would need to phy…

>>to really reap the benefits of entanglement for anything other than microsecond HFT algos

These systems are high latency as they often are supplemented by classical communication and post processing. They are used by banks (in Switzerland) to do secure point-to-point communication. But they only protect the channel and not the copy of Windows 2000 running on either end.

Re: Two Big Steps Toward the Quantum Computer

#14

I was under the Belief that we currently have no way of adding the qbits together. We can set a qbit and read it but we can't currently get the particles in the quantum state to interact. The article however paints another picture.

Some groups have even been running Shor's algorithm on multi-qubit computers. https://en.wikipedia.org/wiki/Quantum_computer#Developments It requires the qubits to be entangled to do the computation, and in the later ones (not IBM's 2001 work) the researchers did observe entanglement.

Re: Two Big Steps Toward the Quantum Computer

#15
post #7

Earlier quoted context omitted.

how would you entangle the photons in the first place? from what i understand they have to be in close proximity or even emitted from the same source. once entangled, they need to be maintained in this state very very carefully. i think a few hours is the record currently. to really reap the benefits of entanglement for anything other than microsecond HFT algos, like for human telecommunication, you would need to phy…

Yeah, not saying this was possible now. But in 10, 20 years? Perhaps they can be entangled at the factory in the "special room" then kept stable over the next 10 years. That would be enough, no?

Sure. Last year, they stopped a photon for a solid minute. http://www.extremetech.com/extreme/162289-light-stopped-comp... Note this preserves the quantum state of the photon - it's not just storing the energy and then re-emitting a different photon.

Re: Two Big Steps Toward the Quantum Computer

#16

When two network quantum chips can communicate instantly (not at speed of light--instantly) over infinite distances, using entangled atoms, then we can ditch the tecos. I'm so looking forward to that.

Faster-than-light communication using entanglement is not possible, according to the standard rules of quantum mechanics. (Dropping some credentials doesn't seem inappropriate here: I worked professionally as a researcher on quantum computing and quantum information for 13 years.)

[deleted]

Re: Two Big Steps Toward the Quantum Computer

#18

When two network quantum chips can communicate instantly (not at speed of light--instantly) over infinite distances, using entangled atoms, then we can ditch the tecos. I'm so looking forward to that.

If at any point in the future of human history FTL travel or communications gets invented, we would already know about it.

Re: Two Big Steps Toward the Quantum Computer

#19
post #15

Earlier quoted context omitted.

Yeah, not saying this was possible now. But in 10, 20 years? Perhaps they can be entangled at the factory in the "special room" then kept stable over the next 10 years. That would be enough, no?

Sure. Last year, they stopped a photon for a solid minute. http://www.extremetech.com/extreme/162289-light-stopped-comp... Note this preserves the quantum state of the photon - it's not just storing the energy and then re-emitting a different photon.

It is my limited understanding that the idea of "a different photon" would be sort of irrelevant here as quantum state is the only thing that differentiates objects such as photons from one another. Outside of that, photons are essentially fungible. I don't really understand the finer points of the experiment however and I could be totally wrong in my understanding.

Re: Two Big Steps Toward the Quantum Computer

#20

When two network quantum chips can communicate instantly (not at speed of light--instantly) over infinite distances, using entangled atoms, then we can ditch the tecos. I'm so looking forward to that.

If at any point in the future of human history FTL travel or communications gets invented, we would already know about it.

As far as I understand, faster-than-light communication violates causality in some reference frames but not in all. FTL communication without arbitrary tims travel might be possiblem
Post reply on HN