Hi.

Yes, a physicist can work in robotics field. you can work as scientific technician or analyst in side with the engineers. but you cant go for building robots directly.

If you have bsc physics, do your msc is engineering physics or electrical physics, then you can work with robotics engineer and with essential skills, you can also build your own robots,

but to be a robotic sciemtist, you atleast need a msc in physics.

Feel free to ask any doubts in comments.