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VW Solves Quantum Chemistry Problems on a D-Wave Machine

spectrum.ieee.org

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Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#31

Post by jcoffland »

zaroth wrote: post #4
Havoc wrote: post #2

>For beginners, he says, an actual D-Wave device isn’t even necessary. I find this somewhat surprising. If you think of AI code designed for GPUs, there I can see "yeah you can practice on a CPU". It'll suck but it'll work. For quantum tech the entire sales pitch is that it's fundamentally different...doing what's near impossible on conventional hardware. Yes I realise he's talking about the library so annealing on a…

I think the performance of the actual device is so limited it’s like running an iPhone simulator to debug your software. But if the expected performance of the quantum machine is theoretically going to increase exponentially every X months for the next 2 decades, combined with the theory that certain problems shift from exponential to polynomial time solutions, yes, eventually the “debugger” will not be useful to act…

But quantum computing performance hasn't increased exponentially in the last X months.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#32

Post by empath75 »

Havoc wrote: post #2

>For beginners, he says, an actual D-Wave device isn’t even necessary. I find this somewhat surprising. If you think of AI code designed for GPUs, there I can see "yeah you can practice on a CPU". It'll suck but it'll work. For quantum tech the entire sales pitch is that it's fundamentally different...doing what's near impossible on conventional hardware. Yes I realise he's talking about the library so annealing on a…

Everything I’ve read says that the d-wave isn’t a real quantum computer.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#33

Post by _Nat_ »

AlexCoventry wrote: post #15

What's the business motivation of this research, for VW?

They probably sold it to management as exploring future simulation-and-optimization methodologies.

I mean, right now, the D-Wave computers seem too weak to be worth the expense compared to classical computers. So, it seems unreasonable for them to expect near-term practicality from this sort of investigation.

But in principle, if D-Wave systems greatly improve to the point that they're competitive with classical optimizers, then it'd be good for VW engineers to be able to leverage them to do stuff like, in this case, predict chemical properties.

This seems to be how the article sells it:

> “Our present work was a first field study of quantum chemistry problems on quantum annealing devices,” he says. “Our goal was to get a feeling for the bottlenecks of the problem. This in the end helps [us] to understand the underlying problems, and find new solutions or suitable subproblems.”

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#34

Post by jlg23 »

iamgopal wrote: post #6

VW also does science ? Nice to know. Is it related to battery technology etc ? Or such companies usually invest in fundamental research ?

From the article: His group’s paper runs down a wish list of quantum chemistry simulations that sufficiently robust quantum computation should be able to tackle. Such problems include designing next-generation batteries, optimizing solar cells via detailed study of photosynthesis, and faithfully simulating complex molecules without resorting to approximations that conventional computers must rely on to make the simulations tractable.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#36

Post by krastanov »

williamscales wrote: post #11
jf- wrote: post #8

Earlier quoted context omitted.

Presumably because that’s just a matter of scale. The calculation didn’t turn out wrong, the machine just isn’t powerful enough to calculate it. All of this work is proof of concept for more powerful devices down the road, the point isn’t that it’s better than a classical computer right now.

Is there any evidence it will ever be better than a classical computer?

There is no evidence that quantum annealing (what D-Wave does) is any better than classical computers.

There is a lot of evidence that quantum computers (the gate model) or, equivalently, quantum adiabatic computing is better than classical computing. All of it is based on a family of conjectures about the complexity classes P, BQP, and NP.

Scott Aaronson's blog is one of my go-to suggestions for rigorous introduction to the topic.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#37

Post by krastanov »

Havoc wrote: post #2

>For beginners, he says, an actual D-Wave device isn’t even necessary. I find this somewhat surprising. If you think of AI code designed for GPUs, there I can see "yeah you can practice on a CPU". It'll suck but it'll work. For quantum tech the entire sales pitch is that it's fundamentally different...doing what's near impossible on conventional hardware. Yes I realise he's talking about the library so annealing on a…

"Quantum tech" is regrettably much too overloaded of a term.

The "quantum annealers" that D-Wave sells are not known to be more powerful than classical computers. For the moment, at best, they are interesting analog computers.

Quantum computers (either the circuit model or equivalently the quantum adiabatic computer model) are conjectured to be much more powerful than classical computers, but they are quite a bit different from D-Wave's quantum annealers (for starters, they are supposed to be able to keep all their qubits in a pure entangled state, which D-Wave definitely can not do). There are various experimental hardwares that are able to keep a handful of qubits entangled, but we will need thousands (if not millions) before being able to do anything useful with them.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#38

Post by steve_musk »

jf- wrote: post #8
twtw wrote: post #5

... and couldn't get the correct answers for LiH. Interesting that the article didn't mention this. From the paper: > For lithium hydride, LiH, we were not able to reproduce closely the ground state energy with the currently available hardware. When accounting for 3 orbitals and using a scaling factor of r = 4, we already had to use 1558 qubits, which is a large fraction of available qubits. To summarize: the investi…

Presumably because that’s just a matter of scale. The calculation didn’t turn out wrong, the machine just isn’t powerful enough to calculate it. All of this work is proof of concept for more powerful devices down the road, the point isn’t that it’s better than a classical computer right now.

Well scaling is the problem when dealing with quantum chemistry.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#39

Post by delecti »

iamgopal wrote: post #6

VW also does science ? Nice to know. Is it related to battery technology etc ? Or such companies usually invest in fundamental research ?

Quantum computing is also of interest to self-driving cars. I know that at least some other big car companies do quantum computing work for that reason. I wouldn't be surprised if this is a test of sorts.

Re: VW Solves Quantum Chemistry Problems on a D-Wave Machine

#40

Post by KKKKkkkk1 »

twtw wrote: post #21
jf- wrote: post #8

Earlier quoted context omitted.

Presumably because that’s just a matter of scale. The calculation didn’t turn out wrong, the machine just isn’t powerful enough to calculate it. All of this work is proof of concept for more powerful devices down the road, the point isn’t that it’s better than a classical computer right now.

Right, and the paper itself is very upfront about that. I don't have any objection to the research, which is likely very valuable, but I do find it strange that the article claims they solved two problems without mentioning that only one of the solutions was correct. It would be great if the article said they solved one and made good progress on techniques for the second that will likely work on next generation hardw…

> It's like the U.S. national labs unveiling the world's first exaflop supercomputer, with a footnote indicating that in fact the computer is only 100 petaflops at the moment.

Can you add context?

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