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Willow, Our Quantum Chip

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Re: Willow, Our Quantum Chip

#201

Post by currymj »

goatking wrote: post #51
vessenes wrote: post #18

I’m a quantum dabbler so I’ll throw out an armchair reaction: this is a significant announcement. My memory is that 256 bit keys in non quantum resistant algos need something like 2500 qubits or so; and by that I mean generally useful programmable qubits. To show a bit over 100 qubits with stability, meaning the information survives a while, long enough to be read, and general enough to run some benchmarks on is some…

How can I, a regular software engineer, learn about quantum computing without having to learn quantum theory? > Worth spending a little time doing some long tail strategizing I’d say any tips for starters?

specifically avoid resources written by and for physicists.

the model of quantum mechanics, if you can afford to ignore any real-world physical system and just deal with abstract |0>, |1> qubits, is relatively easy. (this is really funny given how incredibly difficult actual quantum physics can be.)

you have to learn basic linear algebra with complex numbers (can safely ignore anything really gnarly).

then you learn how to express Boolean circuits in terms of different matrix multiplications, to capture classical computation in this model. This should be pretty easy if you have a software engineer's grasp of Boolean logic.

Then you can learn basic ideas about entanglement, and a few of the weird quantum tricks that make algorithms like Shor and Grover search work. Shor's algorithm may be a little mathematically tough.

realistically you probably will never need to know how to program a quantum computer even if they become practical and successful. applications are powerful but very limited.

"What You Shouldn't Know About Quantum Computers" is a good non-mathematical read.

https://arxiv.org/abs/2405.15838

Re: Willow, Our Quantum Chip

#202

Post by TachyonicBytes »

fguerraz wrote: post #108

Am I oversimplifying in thinking that they’ve demonstrated that their quantum computer is better than at simulating a quantum system than a classical computer? In which case, should I be impressed? I mean sure, it sounds like you’ve implemented a quantum VM.

Simulating a quantum system is a hard challenge and it's actually how Feynman proposed the quantum computing paradigm in the first place. It's basically the original motive.

Re: Willow, Our Quantum Chip

#203

Post by pdabbadabba »

kridsdale1 wrote: post #113
0xB31B1B wrote: post #72

Earlier quoted context omitted.

"Also, what is the relationship, if any, between quantum computing and AI? Are these technologies complementary?" AI is limited in part by the computation available at training and runtime. If your computer is 10^X times faster, then your model is also "better". Thats why we have giant warehouses full of H100 chips pulling down a few megawatts from the grid right now. Quantum computing could theoretically allow your…

Makes sense. My brain is able to do that work on milliwatts.

Actually about 20 W — if you ignore the 80 W used by the rest of the body (which seems debatable). And clearly far more than this was required to 'train' the human brain to the level of intelligence we have today.[1] But this still probably doesn't take away from your point. The human brain seems to be many orders of magnitude more efficient than our most advanced AI technology.

Though the more I think about this, the more I wonder how they really would compare if you made a strictly apples-to-apples comparison.

[1] https://psychology.stackexchange.com/questions/12385/how-muc...

Re: Willow, Our Quantum Chip

#204

Post by numpad0 »

isoprophlex wrote: post #84
vessenes wrote: post #18

I’m a quantum dabbler so I’ll throw out an armchair reaction: this is a significant announcement. My memory is that 256 bit keys in non quantum resistant algos need something like 2500 qubits or so; and by that I mean generally useful programmable qubits. To show a bit over 100 qubits with stability, meaning the information survives a while, long enough to be read, and general enough to run some benchmarks on is some…

Data security okay. But AI? How will that change?

Aren't quantum computers expected to be like digitally read analog computers for high dimension optimization problems, and AI is like massive high dimension optimization problems?

Re: Willow, Our Quantum Chip

#205

Post by npalli »

vessenes wrote: post #18

I’m a quantum dabbler so I’ll throw out an armchair reaction: this is a significant announcement. My memory is that 256 bit keys in non quantum resistant algos need something like 2500 qubits or so; and by that I mean generally useful programmable qubits. To show a bit over 100 qubits with stability, meaning the information survives a while, long enough to be read, and general enough to run some benchmarks on is some…

> Worth spending a little time doing some long tail strategizing I’d say.

Yup, like Bitcoin going to zero.

Re: Willow, Our Quantum Chip

#206

Post by kvathupo »

zitterbewegung wrote: post #159
raidicy wrote: post #88

Earlier quoted context omitted.

Are there any insights that you can give based off the info you've learned about quantum computation that you might not have been able to reach if you hadn't learned about it? From my __very__ shallow understanding, because all of the efficiency increases are in very specific areas, it might not be useful for the average computer science interested individual?

Nearly all of quantum computation is theoretical algorithms and the hard engineering problems haven't been solved. Most of the math though has a large amount of overlap of AI / ML and all of deep learning to the point that Quantum computers could be used as "ML accelerators" by using algorithms (this is called Quantum Machine learning) [1]. Quantum computing could be learned with a limited understanding of Quantum th…

Possibly of interest, but I wrote a (hopefully approachable) report on quantum perceptrons a few years back [1]. Perhaps it's found elsewhere, but I was surprised by how, at least in this quantum algo's case, the basis of training was game theoretic not gradient descent!

[1] - https://kvathupo.github.io/cs/quantum/457_Final_Report.pdf

Re: Willow, Our Quantum Chip

#208

Post by ajb »

goatking wrote: post #51
vessenes wrote: post #18

I’m a quantum dabbler so I’ll throw out an armchair reaction: this is a significant announcement. My memory is that 256 bit keys in non quantum resistant algos need something like 2500 qubits or so; and by that I mean generally useful programmable qubits. To show a bit over 100 qubits with stability, meaning the information survives a while, long enough to be read, and general enough to run some benchmarks on is some…

How can I, a regular software engineer, learn about quantum computing without having to learn quantum theory? > Worth spending a little time doing some long tail strategizing I’d say any tips for starters?

The simplest algorithm to understand is probably Grover's algorithm. Knowing that shows you how to get an sqrt(N) speedup on many classical algorithms. Then have a look at shor's algorithm which is the classic factoring algorithm.

I would not worry about hardware at first. But if you are interested and like physics, the simplest to understand are linear optical quantum circuits. These use components which may be familiar from high school or undergraduate physics. The catch is that the space (and component count) is exponential in the number of qubits, hence the need for more exotic designs.

Re: Willow, Our Quantum Chip

#209

Post by LeftHandPath »

softwaredoug wrote: post #194
LeftHandPath wrote: post #180

Earlier quoted context omitted.

I did quantum computing research in university. We did meaningful work and published meaningful research. Around 50% of our time was spent working in Overleaf making small improvements to old projects so that we could submit to some new journal or call-for-papers. We were always doing peer review or getting peer reviewed. We were working with a lot of 3rd-party tools (e.g. FPGAs, IBM Q, etc). And our team was constan…

I wonder what makes research different than product development at a company? Because in product development, there can be short-sighted industry decisions based on quarterly returns. I've also seen a constant need to justify outcomes based on KPIs etc, and constantly justifying your work, etc.

Research is product development. Successful companies treat it with respect.

> Because in product development, there can be short-sighted industry decisions based on quarterly returns. I've also seen a constant need to justify outcomes based on KPIs etc, and constantly justifying your work, etc.

I have seen this as well. It's extremely common (especially among publicly-owned companies) and frustrating. But it's not ubiquitous. Consider LM's Skunkworks or Apple's quiet development of the iPhone, and compare it to companies that finish a product and then focus on cutting costs / nickel-and-diming their customers.

Re: Willow, Our Quantum Chip

#210

Post by pclmulqdq »

adastra22 wrote: post #184
JanisErdmanis wrote: post #77

Earlier quoted context omitted.

The required number of qubits to execute Shor’s algorithm is way larger than 2500 qubits as the error ceiling for logical qubits must decrease exponentially with every logical qubit added to produce meaningful results. Hence, repeated applications of error correction or an increase in the surface code would be required. That would significantly blow up the number of physical qubits needed.

He’s quoting the number of logical qubits (which is 1024 IIRC, not 2500), after error correction. ETA: Wikipedia 2330 qubits, but I'm not sure it is citing the most recent work: https://en.wikipedia.org/wiki/Elliptic-curve_cryptography#ci...

1024 is for RSA-1024, which is believed to be broken by classical means at this point. Everyone doing anything with RSA is on 4k or larger.
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