Currently I'm a junior math and physics major from the US expecting to graduate May 2015 with a bs in math and ms in physics after 4 years. I'm spending a semester abroad in Australia this semester and I'm realizing I would like to try spending a few years in Europe, preferably around Scandinavia. I'm planning on doing my PhD in quantum information theory or theoretical particle physics/string theory, but after graduate school I'm not necessarily set on going into academia, but I don't exactly know what other jobs I can get with a PhD in these fields, let alone if I get a PhD from a European institution. I'm not 100% set on staying in physics either, it's ideal but I wouldn't mind getting a job in another field. I do want to keep my options of working in America open as well, from what I understand if I get my PhD in Europe, unless I go to Oxford or Cambridge my degree can mean less than if I get it from an American institution? If that's the case then I could see myself going for a post-doctoral position in Europe instead if that's feasible, but putting off living there for 4-6 years doesn't seem too ideal for me. Does anyone have any experience with this? I don't want to get a job for a few years of my life then find out that when I get back to America it amounts to very little on my resume/CV. Will it hurt my job search if I decide to leave physics as much as if I decide to stay in physics?