As an incoming PhD student, what’s the etiquette surrounding changing advisors before my first day?
I’m an incoming 1st year PhD student in the physics program at an American university. Initially, I was interested in working in Professor A’s group, and before committing to the program I reached out to them to confirm that they have the funding to take me on as a student.
However, that was in April, and in the meantime I’ve had the chance to gain experience in an adjacent subfield that aligns much more with the work done by Professor B. I’ve realized through this new experience that I would much prefer to continue this same type of research during my PhD, and that I would prefer to work with Professor B. I’ve reached out to them and confirmed that they have funding for me to do so as well.
However, one big issue is that I verbally confirmed my interest in working with Professor A back in April (although to my knowledge they never signed the forms to make them my official advisor). What’s more, A is in the Electrical Engineering department, which admits directly to a PI’s lab instead of the program at large. Because of my initial verbal commitment, Professor A’s group denied admission of an additional PhD student in order to have the funding available for me. I feel awful about backing out now, but I’ve realized working with Professor B would be much better for me overall. How should I handle this situation?
TLDR: I informally committed to joining lab A, but before my first day I’m looking to change to lab B and I’m wondering what the etiquette surrounding that is