I like the name "Quantum Computing", for this SE.
It's sexier than just "Quantum".
So I'm not suggesting to change it.

But that doesn't mean questions have to be only about quantum computing.

In my mind the following are also related enough to be appropriate

  • quantum communication
  • quantum information
  • quantum metrology
  • boson sampling (it's not "computing", but it's related)
  • quantum annealing
  • classical algorithms for quantum simulation (not necessarily of QC)

Most "quantum computing" research groups work in many of the above areas.

When I entered my PhD I was hoping to work on quantum computing, and the group had been working on quantum computing for over a decade, and still was during my interview process, but when I arrived at Oxford, the group had shifted their interest into a new topic that was sexy at the time, called "quantum biology".

We've already had a quantum biology question here: Quantum simulation of environment-assisted quantum walks in photosynthetic energy transfer

And this was actually the first question I answered, on my first day on this SE. I is what got me the reputation to start participating more actively on this SE.

Recently we have had a question of whether or not quantum foundations questions are appropriate:

Is there a way that surreal maths can be used in quantum theory?

Funny enough, I also had wished to pursue quantum computing for my undergraduate thesis and joined Ray Laflamme's group (Director of the Institute for Quantum Computing at the time), but his interest at the time was not in quantum computing but in the "3-slit experiment" which had its heart in quantum foundations.

The "Institute for Quantum Computing" has lots of people working in Quantum Foundations or "Quantum Information" or "Quantum Communication" more than "Quantum Computing". If that can be the case, then why can't we welcome quantum foundations questions here? It gives us more views, more questions, and ultimately, people here are more likely to give a good answer about quantum related things here than on the physics SE. I don't go to the physics SE unless I have a specific question, but I browse here because it's fun.

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    $\begingroup$ I feel discussions about quantum foundations should be welcome here (unless it drifts off into fringe-physics/crackpot territory). It's in some sense relevant to quantum information theory (which is on-topic). However, I didn't like @meowzz's question as such since it doesn't give any explanation as to why/how "surreal numbers" are relevant and how the question is related to "categorical quantum mechanics" (the now-removed tag). The question seems to be a collection of vaguely related quotes picked up from Physics SE and other places. I voted to close it due to lack of "research effort". $\endgroup$ Commented Jul 13, 2018 at 15:20
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    $\begingroup$ @Blue: I would welcome "crackpot" questions, but that's just me. Galileo and Einstein asked (and answered) questions that were "crackpot" questions at the time. Meow's question was not clear at first, but it turned out that s/he was asking "if surreal numbers are relevant". The categorical quantum tag was an error because s/he didn't know what it was. It does seem there was a lot of research effort, based on the amount of links to other articles s/he gave, and the fact that s/he has a bounty on a related physics SE question. If all quantum questions from Physics SE go here, I don't mind that! $\endgroup$ Commented Jul 13, 2018 at 15:26

3 Answers 3


I think this stack is the quantum stack.

Before seeing this question on meta I created the quantum-foundations tag (please expand tag wiki if you have the competency) because I think foundations are fundamental.

I like James' approach of leaving questions open vs. closing for being off-topic unless they truly have nothing to do w/ quantum. There are a few older questions that I think are interesting that have already been closed, unfortunately.

I ended up on this stack after asking a question on the physics stack that was quantum related because there was a similar question that had already been asked. The question was "closed as unclear what you're asking" on the physics stack vs welcomed here (see James' comment on my question) & is actually the best received question I have asked (based on votes).

I think maintaining an open environment for those that are learning is an important element in ensuring this stack continues to grow & thrive, since itself is still very young.


I always think of this as a quantum information SE, but with the sexier 'Quantum Computing' name. So I would personally consider all of your bullet points on topic, except maybe for the last.

Quantum foundations is a very broad field. There are parts that are certainly on-topic. Discussions of Bell's theorem, for example, fit very well with quantum crypto and teleportation.

There are also parts that are less on-topic, like imagining alternatives to QM. This would constitute new physics, and so I'd say that it belongs on the Physics SE instead.

There is no easy way to draw this line, though. If we allow a discussion of security for blind quantum computing, why not a discussion of how that security might be affected by possible post-quantum theories? Then we will have already entered the wilder realms of quantum foundations.

I think the best option for this young SE would be to treat the less obviously on-topic questions on a case-by-case basis, and try to figure out more concrete rules as we go along.

Personally, I tend to prefer to allow questions rather than close them for being off-topic.


My suggestion would be to allow quantum foundations questions.
In fact if all "quantum" questions from Physics SE go here, I don't mind that!

Users may still wish to ask quantum questions on the Physics SE (such as quantum gravity questions) but that's up to the user whether they prefer to have their question seen mainly by us, or if it benefits them more to ask somewhere else.

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    $\begingroup$ By all "quantum" questions, you mean quantum field theory and the like as well, and only leave the classical physics at physics.se? $\endgroup$ Commented Jul 14, 2018 at 8:44
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    $\begingroup$ @Norbert, if the user chooses to ask a quantum gravity question here rather than the physics SE, that might be because they prefered to get perspective from people with a quantum info background. That's up to them. If they don't get answers it can be "moved" to physics just like my question on whether the 2015 Shor algorithm implementation is actually scalable, got moved from physics to computer science to theoretical computer science because it wasn't getting answers, then finally got an answer from Peter Shor. This is better than "closing" the question as "off-topic". $\endgroup$ Commented Jul 14, 2018 at 13:48
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    $\begingroup$ Depending on context, a quantum gravity question can or cannot have use for quantum information perspective. Like say you were asking to compute a graviton scattering, then it is not like here would offer anything different or better than physics SE. But if the question was something like holography then it would fit squarely within quantum information/computing. So my opinion would be close/migrate the first question, but upvote the second. I don't have a general rule, but we can build that up from examples like these. $\endgroup$
    – AHusain
    Commented Nov 3, 2018 at 19:50

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