This depends. How easily can you get relevant experience in your PhD vs in the workplace?
PhD research typically is centered on deep investigation of a specific niche, and depending on where you are, that may be more easily accomplished in either scenario.
More relevant to your question is what do you want to do with either your PhD, or the relevant work experience in physics? What impact do you want to make with that knowledge?
- Do you want to continue investigating interesting intellectual topics?
- Do you want to move into solving practical world problems?
- Do you want to voyage into the business world?
- Do you want to live in a situation where you’re primarily responsible for your own work, or do you want to manage a team?
- Do you want to teach and mentor others?
If you provide more information about these aspects of your personality and preferences, or take the time to find this out, this will ultimately help you be successful, no matter which professional development path you end up taking.
“How easily can you get relevant experience in your PhD vs in the workplace?”