Nanotechnology is a interdisciplinary field. Scientists and Engineers in physics, chemistry, material science, mechanical, electrical, chemical, and biomedical engineering are working together in this field. Some schools, such as UCSD are starting NanoEngineering majors. In other places, going into any of the above majors can lead to a potential career in nanotechnology. Engineering math is taught in any of these engineering majors and is a useful tool. A profound understanding of physics and chemistry will be important too. Physics, mechanical, and electrical engineering may emphasize more on physics, where as chemistry, chemical, and biomedical engineering will give you more training on chemistry. Material science is probably a little of both. Based on your other interests, you can choose any of these majors.