* University of California, Berkeley (UC Berkeley): A world-renowned institution with a very strong and large physics department, offering a wide range of specializations.
* California Institute of Technology (Caltech): Known for its intense focus on science and engineering, Caltech has a highly competitive and prestigious physics program.
* Stanford University: Another top-tier university with a strong physics department, often focusing on areas with strong ties to other disciplines like applied physics and engineering.
* University of California, San Diego (UC San Diego): Offers a diverse range of physics research areas, including theoretical, experimental, and computational physics.
* University of California, Los Angeles (UCLA): A large university with a substantial physics department covering many subfields.
* University of California, Santa Barbara (UCSB): Strong in theoretical physics and condensed matter physics, with a particular emphasis on materials science.
* University of California, Davis (UC Davis): Offers PhD programs in physics with a focus on areas like high-energy physics and cosmology.
* University of California, Irvine (UCI): Provides PhD programs in physics with strong programs in several areas.
* San Jose State University: While not as prestigious as the UC system or Caltech/Stanford, SJSU offers a physics PhD program, often with a more applied focus.
This list isn't exhaustive, and other universities in California might offer PhD programs with a physics component as part of a broader program (e.g., applied physics, astrophysics within astronomy). To find a truly complete list, it's best to search online using keywords like "PhD physics California" and browse the websites of individual universities. You should also consider the specific area of physics you're interested in, as different universities have different strengths and specializations within the field.