Apply online at Cal State Apply. No separate application to the department is required.In your Cal State Apply application, your statement of purpose should contain:

your goals beyond the Master's degree (what do you plan to do with the degree), and
what Physics research you would like to pursue in the department if admitted.
BS or BA
GPA > 2.5
No GRE required
TOEFL > 550 or >80 (iBT) (for international students)

Have earned a grade point average of at least 2.5 on the last degree completed by the candidate or have attained a grade point average of at least 2.5 (A=4.0) in the last 60 semester (90 quarter) units attempted.

IELTS - 6.5