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Quantum Development Kit preview

blogs.microsoft.com

31–40 of 55 posts

Re: Quantum Development Kit preview

#32
post #22

I'm legitimately excited by quantum computing. The field is moving SO much faster than popular knowledge, which seems to believe a quantum computer will arrive at the same time as a workable fusion reactor. Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM![0] Google and Microsoft are both dumping resources into creating commercially-available quantum computers. Google sa…

Your comment made me wonder: would quantum computing help with simulating plasma dynamics in a way that would help us improve fusion reactors?

Re: Quantum Development Kit preview

#34
A quote from Microsoft's video: "[A] computer that computes in a billion parallel universes at the same time".

This is a bold statement with no physical evidence to backup and no idea how quantum computer works.

Re: Quantum Development Kit preview

#35
post #28
post #18

Earlier quoted context omitted.

Q# code is run on a quantum virtual machine; which is a program that simulates a quantum computer on a classical computer. Quantum computers can be simulated by classical computers up to a certain point. Like that article says, a 30 qubit quantum computer can be simulated on a laptop. Microsoft is simulating up to 40 qubits on Azure. Simulating around 50 qubits or so would need one of the world's most powerful superc…

Quantum computers can be simulated by classical computers up to a certain point. Note that the 'certain point' here is a practical limit of time/efficiency. In terms of computability, anything that can be computed on a quantum computer can be computed on a classical computer with exponential slowdown. It's the exponential slowdown that results in the practical limit.

And anything that can be computed on a classical computer can be computed with pebbles, the practical limits matter. ;-)

Re: Quantum Development Kit preview

#36
post #26
post #22

I'm legitimately excited by quantum computing. The field is moving SO much faster than popular knowledge, which seems to believe a quantum computer will arrive at the same time as a workable fusion reactor. Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM![0] Google and Microsoft are both dumping resources into creating commercially-available quantum computers. Google sa…

"Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM!" Let's be a bit realistic. It's a 5 qubit processor. I'm not sure how excited the general population were when the first 5 bit processor was available. There is still a ways to go before actually useful quantum computers are generally available. "You have access to one now with the Quantum Experience. It is small at the…

Is that a legitimate analogy? My understanding is that the number of qbits of a quantum computer are not fairly compared to the number of classical bits needed in order to make a useful computation.

Re: Quantum Development Kit preview

#37
post #26
post #22

I'm legitimately excited by quantum computing. The field is moving SO much faster than popular knowledge, which seems to believe a quantum computer will arrive at the same time as a workable fusion reactor. Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM![0] Google and Microsoft are both dumping resources into creating commercially-available quantum computers. Google sa…

"Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM!" Let's be a bit realistic. It's a 5 qubit processor. I'm not sure how excited the general population were when the first 5 bit processor was available. There is still a ways to go before actually useful quantum computers are generally available. "You have access to one now with the Quantum Experience. It is small at the…

The comparison between qbits and classical bits is somewhat specious.

qbits allow up to twice as many 'states' per bit when compared to classical bits.[0]

As for the public excitement, that will depend on someone making something exiting with the x bits available.

[0]https://youtu.be/w5rCn593Dig

Re: Quantum Development Kit preview

#38
post #36
post #26

Earlier quoted context omitted.

"Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM!" Let's be a bit realistic. It's a 5 qubit processor. I'm not sure how excited the general population were when the first 5 bit processor was available. There is still a ways to go before actually useful quantum computers are generally available. "You have access to one now with the Quantum Experience. It is small at the…

Is that a legitimate analogy? My understanding is that the number of qbits of a quantum computer are not fairly compared to the number of classical bits needed in order to make a useful computation.

It's even more limiting. A 5 qubit computer can get the expected efficiency of a quantum algorithm that needs a working memory of less than 5 qubits. That's it. Furthermore, the scaling is entirely different - a 8 bit computer can simulate 16-bit calculations with a limited number of primitives - e.g. a 16-bit multiply can be made with four 8-bit multiplies; but the quantum operations don't stack that way; you have to "read" the values in between, collapsing all the quantum states.

So for quite a few algorithms there are no efficient ways to stretch the size limit, you're back to brute force. If you have a quantum computer that allows you to e.g. break a 128 bit keys, then factoring a 129 bit key takes twice as much time, a 130bit key takes four times as much, and a 256 bit key takes 2^128 times as much time.

Re: Quantum Development Kit preview

#40
post #32
post #22

I'm legitimately excited by quantum computing. The field is moving SO much faster than popular knowledge, which seems to believe a quantum computer will arrive at the same time as a workable fusion reactor. Real quantum computers exist RIGHT NOW. You can even write a program and run it on one from IBM![0] Google and Microsoft are both dumping resources into creating commercially-available quantum computers. Google sa…

Your comment made me wonder: would quantum computing help with simulating plasma dynamics in a way that would help us improve fusion reactors?

Almost certainly not. The quantum computer is useful to get around the exponential scaling of problem difficulty in simulating quantum systems. In plasma physics that's not the issue. It's the crazy large size of the problem that scales in a classical and otherwise reasonable manner.
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