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Getting the World Quantum Ready

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Re: Getting the World Quantum Ready

#5

Post by archgoon »

extide wrote: post #2

Am I missing something because D-Wave has 1024 qubit machines available now and 2000 qubit ones soon.

I'm going to repost from a year ago:

D-Wave isn't trying to build a general purpose quantum computer. As it stands, they've been trying to optimize a computer that executes a particular algorithm (and as it stands, it's not faster than optimized classical algorithms). It is an open research question if D-Wave's architecture actually utilizes any quantum effects to give it an advantage over classical architectures. D-Wave hopes that it does, and that there will be enough problems that their machine is good at that their approach will be justified.

D-Wave markets themselves as having hundreds or thousands of qubits, but these qubits aren't easily controllable or measurable in ways that would allow Shor's Algorithm to be executed on them (for example), so at the least, it seems like dishonest marketing. In order to build a general quantum computer, you need to be able to apply gates to arbitrary collections of qubits.

Re: Getting the World Quantum Ready

#7

Post by extide »

archgoon wrote: post #5
extide wrote: post #2

Am I missing something because D-Wave has 1024 qubit machines available now and 2000 qubit ones soon.

I'm going to repost from a year ago: D-Wave isn't trying to build a general purpose quantum computer. As it stands, they've been trying to optimize a computer that executes a particular algorithm (and as it stands, it's not faster than optimized classical algorithms). It is an open research question if D-Wave's architecture actually utilizes any quantum effects to give it an advantage over classical architectures. D-…

Ah, thanks

Re: Getting the World Quantum Ready

#9

Post by archgoon »

omarforgotpwd wrote: post #6

Can I run Shors algorithm on this? If not, how many qubits would I need for that? If so, how do I short bitcoin?

According to this paper:

https://arxiv.org/abs/quant-ph/0205095

You can implement Shor's algorithm to factor an N-bit number with just 2n+3 qubits. So the 20 qubit processor would be able to factor any 8 bit number (not necessarily faster than a classical computer could, or even a human could, mind you).

Re: Getting the World Quantum Ready

#10

Post by adventured »

benchaney wrote: post #8
omarforgotpwd wrote: post #6

Can I run Shors algorithm on this? If not, how many qubits would I need for that? If so, how do I short bitcoin?

1. Probably 2. Several Thousand [0] 3. You can't, at least not easily [0] https://en.wikipedia.org/wiki/Elliptic-curve_cryptography#Qu...

3. Yes you can easily. The futures contracts have enabled short bets against Bitcoin. A few brokers have set this week or next as a roll-out for that, in the very near future hundreds of different financial companies will enable shorting via futures for their clients.

For example, Interactive Brokers is going live with their shorting this week:

https://www.bloomberg.com/news/articles/2017-12-12/bitcoin-b...

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