Quantum Information in Math Departments I'm currently a graduate student in mathematics getting my master's degree. I am interested in a bit probability and partial differential equations, and, secondarily, a bit of mathematical physics; most likely quantum information theory. I'll most likely be moving to a different graduate program after completing my master's degree from my current institution , and I'm currently trying to figure out whether there are mathematics departments that have research groups in quantum information theory.
I believe I will want to stay in a mathematics department, as I'm not awfully interested in the experimental aspects of quantum information. I'm more interested in the mathematical aspects of the subject, and I'll definitely be applying with the approach where I'll try and cash on my undergraduate background in physics/quantum mechanics, and use my knowledge of math in topology, functional analysis, real analysis etc. to put it to good, meaningful use to solve inter-disciplinary problems.

However, I'm not sure whether there are a large number of math departments in the US that have research groups in quantum information? I know there's one at UC Davis,

http://qmap.ucdavis.edu/,

and I think the math department at UT Austin collaborates heavily with the physics/cs departments, so I won't be surprised if they have people working in quantum information over there.

I'm not, however, sure whether these departments/research groups are anomalies. It'd be great if someone could nudge me in the right answer to this direction? List of math departments doing quantum information? Or should I look at CS/Physics departments*?

*I don't think I will apply to physics schools because I am not really interested in the experimental aspects, and I don't think I can sum up the courage to take both the math/physics GRE this year, for which I will have to study from the scratch.
Sounds like Applied Math.  In terms of a specific PI doing quantum information*, I don't know which school.  But when you mention your course interests and wanting to collaborate with people on real problems that is applied math all the way.

Here is a list of top programs:  https://www.usnews.com/best-graduate-schools/top-science-schools/applied-mathematics-rankings  Not passing judgment, but list gets you started.  I would look at some of their webpages and reach out via email to one or tow and just start educating yourself on what they're like versus what you want.  Maybe do a visit if one near.

You could also consider statistics grad programs.  That is a wonderfully applied field and one where there is some connection to industry, the sciences, etc.

*Music on CDs as opposed to vinyl?