Quantum Development Kit preview | Hacker News Reader

Quantum Development Kit preview

blogs.microsoft.com

197 pointsforrestbrazeal49 comments

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 says it will demonstrate a quantum computer in mere months which outperforms a classical computer on some problem.[1] The real value of quantum computers is not found in breaking RSA. Simulated molecular dynamics sees an exponential speedup over classical methods; this has huge ramifications for drug & material design.[2] What a time to be alive!

I have a BSc in Computer Science, and am teaching myself quantum computing. I'm really liking the book Quantum Computer Science: An Introduction by David Mermin. All this stuff is within your grasp! You aren't required to understand quantum weirdness to use a quantum computer.

[0] https://quantumexperience.ng.bluemix.net/qx/experience

[1] https://www.technologyreview.com/s/609035/google-reveals-blu...

[2] https://www.chemistryworld.com/feature/quantum-chemistry-on-...

I also strongly recommend 'Quantum Computing for Computer Scientists'...this is a really, really good book for those coming from a C.S. background.

I totally agree. It lays out the minimum of the physics and mathematics background needed to get into it as a computer scientist.

I read a news announcement on, I believe, IEEE, that Intel had gotten a manufacturing process down for a 17-qubit chip and had shipped it to their research lab in the Netherlands. There are certainly developments left and right. It will be interesting to see where quantum computing ends up... I could certainly see big possibilities for it in the communications sphere, guaranteeing link integrity and things like that.

"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 moment, with a five-qubit processor, but it is a work-in-progress that we are continually improving."[0]

[0] - https://quantumexperience.ng.bluemix.net/qx/tutorial?section...

At least they seemed pretty exited with Intel 4004.

Did they actually, outside of happy Busicom calculator users? Even 8008 "looked okay, but nobody used it" - http://ethw.org/Oral-History:Masatoshi_Shima

I guess I misread it.

I wanted to convey that there were some groups actually happy about it.

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.

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

> this has huge ramifications for drug & material design

Is the realistically any chance that a significant part of that innovation will happen in startups / new companies, or will this mostly play out in existing pharma/chemistry industry giants?

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.

No, plasma physics is one of the few areas of modern physics in which quantum mechanics is not relevant: https://www.reddit.com/r/AskPhysics/comments/3nohxy/plasma_p...

Well that's a bummer.

I wonder how to reconcile the apparently exciting stuff going on in quantum computing with a conversation I had with a Harvard quantum computing PhD last year (I know very little about the field myself, so I unfortunately can't comment much on specifics here—I just know the guy was legit because of other people I knew who worked with him): he said he'd chosen the wrong field 'cause it has basically played out that quantum computing is intrinsically more limited and less exciting than what people had hoped for, and that a lot of big companies were starting to realize they'd wasted tons of money on it. (This was admittedly all being stated in an exaggerated and joking style, but he did seem serious about the basic idea.) Has there been something in the last year that's changed things? Or maybe his opinion was just an outlier?

Edit: that could've been up to two years ago, thinking about it.

Q# looks quite nice.

https://docs.microsoft.com/en-us/quantum/quantum-qr-intro?vi...

Nice to see Microsoft's progress in quantum computing. It seems like you can't use this SDK without Visual Studio. If you don't have Visual Studio, you can use LIQUi|> [0]; another quantum SDK from Microsoft.

[0]: https://www.microsoft.com/en-us/research/project/language-in...

"LIQUi|>" is hands-down the worst name for anything I've ever seen. Do they really expect people to write it like that?

The "|>" is an allusion to the bar and angle brackets used in bra-ket notation [0]. I believe LIQUi|> is targeted more toward academic quantum computing researchers, who are likely to recognize/appreciate the reference.

[0]: https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation

I will be honest and say I didn't get the reference!

Don't worry! I study quantum computation, and I didn't notice that the |> was supposed to be a D to form the word LIQUID!

It looks horrible but on the other hand it will be really easy to google.

Also, it is an injoke for people familiar with quantum mechanics.

> it will be really easy to google

Hopefully :)

Sometimes it gets spelled as LIQ𝑈𝑖⏐〉 (http://stationq.github.io/Liquid/) which is different from LIQUi|> (https://www.microsoft.com/en-us/research/project/language-in...), which is different from LIQUID. It all depends on how Google feels about qubits on any given day.

But can you spell it all three ways at the same time?

The exact answer would take more time than I have, so I'll say maybe.

Or you can get Visual Studio Community for free: https://www.visualstudio.com/downloads/

Well, if you don't have Windows, that still doesn't help. And if you don't //want// Windows or Visual Studio, that doesn't help either ;-)

I didn't know that you can use Visual Studio on anything that is not Windows. I'll try to install it.

Edit: Looks like you need Visual Studio Community for this SDK which Microsoft only has a Windows version.

Looks like it's available for Mac as well: https://www.visualstudio.com/thank-you-downloading-visual-st...

Edit: The QDK does not have Mac support yet.

"Visual Studio for Mac" is just a rebrand of another IDE they purchased this past year, it's not feature-equivalent with the real VS AFAIK.

Hi, I'm one of the devs on Q#! We're excited to make this preview release of Microsoft's Quantum Development Kit available on Windows PCs. We're exploring the possibility of supporting other platforms in the future and will share more about this at a later time.

Hi, I'm a dev on Q#, and wanted to help clarify a bit how the Quantum Development Kit relates to LIQUi|〉. Microsoft's Quantum Development Kit is a successor to LIQUi|⟩ and we're excited for you to download it and begin writing Q# code. LIQUi|⟩ is focused on the efficient simulation of a quantum computer on a classical one. Q# is a language that will let you program actual quantum computers (in the future). As such, there are areas where LIQUi|⟩ can currently out-perform Q# when it is used on one of the provided simulators (which are striving to emulate the actual gates on quantum hardware). Over time, more simulators will be provided for Q# that will meet (and exceed) the efficiency of LIQUi|⟩ and at that point, we will fully retire LIQUi|⟩.

Possibly dumb question, but what do you actually run Q# code on?

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 supercomputer.

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. ;-)

“toughest challenges, such as world hunger or the dangerous effects of climate change”

How does quantum computing address world hunger or climate change? Convincing humans to not use fossil fuels or to eat less beef doesn’t need Shor’s algorithm.

Quantum computer would enable systematic approach in areas like material sciences and molecular biology, which today are essentially trial and error.

Thumbs up for QC in general. Thumbs down for hype.

Shor's algorithm is not the only potential application for quantum computers. Simulating quantum mechanics and optimization is what quantum computers will probably be used for in the next couple of years.

Regarding the world hunger and climate change claim. I think they are referring to the fact that quantum computers can simulate quantum chemistry more efficiently compared to classical computers. This article [0] talks about how quantum computers will be used for quantum chemistry; specifically nitrogen fixation.

[0]: https://cen.acs.org/articles/95/i43/Chemistry-quantum-comput...

I have fond memories of running MM simulations on an SGI workstation so I totally grok the potential. Not arguing against the utility of QC - just trying to slow down the hype train. Telling someone that downloading an SDK will anytime soon solve climate change is distracting from the currently available non-QC options we have.

My concern is magic tech solutions to easily solved problems allow lazy humans to keep polluting and point to some phantasmagorical silver bullet in the not too distant future...which inevitably comes much much later than expected.

In short, at current CO2 emission growth rates, the Antarctic ice sheets will melt long before QC allows chemists to produce emission free petroleum use or planet scale carbon capture and sequestration. Let's use those future tools for Mars colonization in 2150, but for now, for our kids' sakes, let's stop making throwaway plastic baubles by the tons, relying on petroleum based fertilizers for Big Mac production, and fix the many very solvable behavioral problems with today's tech.

EDIT: typo

Anyone know how this might impact constraint satisfaction algorithms? Is it possible we'd see something like Prolog being orders of magnitude faster? (Assuming it were re-written for a quantum computer, maybe using something like Q#.)

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.

What other languages are there?

Hopefully once the technology matures and becomes more widespread we get a FOSS alternative. I don't trust Microsoft and would not want to work with a stack that is monopolized by them

I think this is crucial.

Rigetti Computing (where I work) has open-sourced several packages related to quantum programming, including pyQuil: https://github.com/rigetticomputing/pyquil

Check out https://www.rigetti.com/ if you want to work with python.

Reply on news.ycombinator.com