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IBM unveils 127-qubit quantum processor

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Re: IBM unveils 127-qubit quantum processor

#51

Post by jazzyjackson »

krastanov wrote: post #37
jazzyjackson wrote: post #33

Quantum Computers sitting in their cryogenic chambers are such works of art, stacks of giant brass plates and hundreds of heat pipes (or coolant pipes? liquid helium I suppose) twisted and coiling throughout the structure hanging like some steampunk chandelier (why do they hang from above anyway?) EDIT: changed to a few direct links to pics: [0][1][2] The esoteric design reminds me of the Connection Machine blog post…

The pipes you mentioned are microwave conduits (for various control signals).

Thanks! Is my assumption of liquid helium running somewhere correct? I figure that's the only way to reach the temperatures required (single digit kelvins, no?)

Re: IBM unveils 127-qubit quantum processor

#52

Post by krastanov »

StLCylone wrote: post #35
mattwilsonn888 wrote: post #23

Where does this sit on the "applicably breaking secure classical cryptography" spectrum?

There are probably entities saving encrypted data right now for when that day arrives. Brings up many interesting lines of thought beyond "is it breakable right now?"

Does it really though? Every secure system design pretty much assumes that the cryptographic standard will be broken in a few decades. Is there really any secret today that would be problematic if made public 30 years in the future? And that would not have been made public by some other method anyway?

Re: IBM unveils 127-qubit quantum processor

#53

Post by zackbloom »

jazzyjackson wrote: post #51
krastanov wrote: post #37

Earlier quoted context omitted.

The pipes you mentioned are microwave conduits (for various control signals).

Thanks! Is my assumption of liquid helium running somewhere correct? I figure that's the only way to reach the temperatures required (single digit kelvins, no?)

It's much colder than that, single-digit millikelvin. They use He-3/4 dilution refrigerators [1]. Getting things cold and electromagnetically-quiet enough that the quantum state doesn't collapse is a big challenge in the field.

1 - https://en.wikipedia.org/wiki/Dilution_refrigerator

Re: IBM unveils 127-qubit quantum processor

#54

Post by ruuda »

jazzyjackson wrote: post #33

Quantum Computers sitting in their cryogenic chambers are such works of art, stacks of giant brass plates and hundreds of heat pipes (or coolant pipes? liquid helium I suppose) twisted and coiling throughout the structure hanging like some steampunk chandelier (why do they hang from above anyway?) EDIT: changed to a few direct links to pics: [0][1][2] The esoteric design reminds me of the Connection Machine blog post…

They hang from the ceiling because they use evaporative cooling (the high-energy particles escape, and the low-energy particles remain in the bucket), each lower stage a bit cooler than the one above it.

Re: IBM unveils 127-qubit quantum processor

#55

Post by krastanov »

jazzyjackson wrote: post #51
krastanov wrote: post #37

Earlier quoted context omitted.

The pipes you mentioned are microwave conduits (for various control signals).

Thanks! Is my assumption of liquid helium running somewhere correct? I figure that's the only way to reach the temperatures required (single digit kelvins, no?)

It is even worse than single digit Kelvin.

Liquid Nitrogen with pumping: 40 K for a few thousand dollars.

Run of the mill Liquid Helium: 4 K for tens to hundreds of thousands of dollars.

But for these devices you need 15mK which is reachable only if you mix two different isotopes of Helium and pump the mixture into vacuum. Such a device is up to 1M$ and more.

And the insides of that device are in vacuum (actually, air freezing into ice on top of the chip can be a problem). The brass is basically the heat conductor between the chip and the cold side of your pumped He mixture (which is *not* just sloshing inside the whole body of the cryostat where the chips are).

Another reason you do not want the He sloshing around is because you will be opening this to make changes to the device and do not want all the extremely expensive He3 (the special isotope you need for the mixture) to be lost.

Re: IBM unveils 127-qubit quantum processor

#57

Post by vezycash »

bawolff wrote: post #44
baby wrote: post #11

I'm starting to get some fatigue about quantum computer news, and I just dismiss them now. If there really is a valuable breakthrough, everyone will be talking about it for months non-stop so I won't miss it.

That's kind of like saying, i'm tired of political news - if we all actually die in a nuclear holocaust armegedon it will be hard to miss.

It's not like political news. It's like new battery tech news.

Re: IBM unveils 127-qubit quantum processor

#58

Post by tcgv »

adrian_mrd wrote: post #6

As someone who knows little about quantum computing, what is the significance of 127-qubits? (as opposed to classical computing's 128 bits, as a reference)

Computational power for quantum computers goes as 2^n, where n is the number of qubits, so unlike classical computing this machine should be orders of magnitude superior to Google's 53-quibit Sycamore.

If you wanna learn more about the subject, a couple of years back I wrote a introduction to quantum computing for programmers which you may find useful:

- https://thomasvilhena.com/2019/11/quantum-computing-for-prog...

Re: IBM unveils 127-qubit quantum processor

#60

Post by rain1 »

It is incredibly dishonest of them to post this without any details about the noise parameters of the system.

When reading "127-qubit system" you would expect that you can perform arbitrary quantum computations on these 127 qubits and they would reasonably cohere for at least a few quantum gates.

In reality the noise levels are so strong that you can essentially do nothing with them except get random noise results. Maybe averaging the same computation 10 million times will just give you enough proof that they were actually coherent and did a quantum computation.

The omission of proper technical details is essentially the same as lying.

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