Robert Oppenheimer

He took a course in thermodynamics taught by Professor Percy Bridgman.

An excerpt from the article 32 facts about Robert Oppenheimer

He then became interested in experimental physics. Since there were no world-class experimental physics centers in the United States at that time, he was offered the opportunity to continue his studies in Cambridge, in Ernest Rutherford's Cavendish Laboratory in the Department of Physics.

The most prominent physicists of the time - Max Planck, Max von Laue, Albert Einstein - were teaching at European universities.