Hi. I'm an undergrad majoring in maths/physics from a US university now taking a year abroad at university of Bristol (UOB) in UK. After this academic year, I'll go back to study in my home university for a year and then graduate. The quantum information (QI) researches at the department of mathematics at UOB is quite inter-disciplinary and very interesting to me. So I talked with a QI professors here and he told me that he prefers a student to be comfortable with high-level maths and that I should choose carefully which theoretical courses I'm going to take before I graduate. Now, even though I'm technically a math major, I planned to graduate with a minimum number of math courses that I thought useful for physics, because virtually any physics professor at my home university encourage me to do lab researches rather than taking math courses. But I'm perfectly fine with taking theoretical math courses. I enjoy them a lot. In fact, because of what the QI professor said, now I have a practical motivation to take those courses other than just for fun. But the problem is, I've never considered this turn of event before. So far, my courseworks balance theoretical and experimental courses. I even thought that, if I have an opportunity to do experiment, I may be fine with it. But now that I want to go all out on theoretical physics/maths to prepare for this UOB master-PhD program in applied maths, it's never guaranteed that I'll get accepted. So do anyone know of grad school that are good at theoretical QI, and it's realistic to hope to get in? I know there're MIT, Waterloo, OxBridge out there, but the probability to get accepted for theoretical physics is even lower than for experimental physics. (For UOB, at least I can score good grades in the courses that I'm taking.) Or should I still prepare for experimental physics? I'm not considering this option myself because I think it's risky to try to be a jack of all trades in this situation. Thank you for your patience reading my long post.