Applied Physics (APh)

Applied physics is a broad field of study that lies at the intersection of physics and many other fields of science and engineering. The applied physics option at Caltech is accordingly a highly multidisciplinary program that is designed to train students in a broad spectrum of physics and engineering fields at an advanced level. Moreover, it is our goal to cultivate abilities in our graduates to apply this knowledge throughout their lives so as to make technological and scientific breakthroughs at the edge of current knowledge.

Students admitted for graduate study can enter from a broad range of disciplines, but are expected to have a rigorous background in undergraduate mathematics, physics, and engineering. An outstanding four-year undergraduate program in mathematics and sciences may provide a suitable background as well. The qualifications of each applicant will be considered individually. After enrollment, the student will arrange a course of study and research in consultation with members of the faculty and the applied physics option representative.

To receive the doctoral degree in applied physics students must demonstrate the ability to formulate and execute an original program of scientific study. As part of this, a doctoral candidate is expected to develop a deep understanding in a chosen field of specialization; to develop tools with which to assess problems outside one’s field of specialization; to develop rigor and strength in the physical sciences for self-education beyond formal training; and to develop skills to become a productive member of the community of scholars. All students wishing to enter the program must complete a series of preparatory courses, followed by an oral candidacy exam in which the student describes their proposed topic of research and is examined on their knowledge of course subject matter. Upon passing the candidacy examination, students work towards completion of a thesis in consultation with their research adviser. The doctoral degree is awarded upon approval of a written thesis by a faculty committee, and successful defense of the thesis in a final oral examination. There is no separate master’s program in applied physics. However, with the approval of the student’s adviser and the applied physics option representative, the degree of Master of Science in Applied Physics may be awarded after the fulfillment of the course requirements described below.

An interim adviser is appointed for each student upon admission to the graduate program in applied physics. Typically, this person is the applied physics option representative. In consultation with the interim adviser the student will determine a course schedule and identify a faculty research adviser. This most often occurs within the first six months of graduate residence. The faculty adviser is the student’s primary mentor and the student will work in the adviser’s research group to formulate and execute a plan of study leading to the thesis. In consultation with their research adviser, the student will also form a Ph.D. Thesis Advisory Committee. This four-member committee should include the student’s adviser and at least three members of the Caltech professorial faculty from either the applied physics or physics options. The Thesis Advisory Committee will conduct the qualifying examination and also approve the thesis and conduct the thesis defense. The membership of this committee may change between the time of the qualifying exam and the final defense.

To be recommended for candidacy for the Ph.D. degree in applied physics, a student must demonstrate mastery in the following five areas of pure and applied physics:

• Classical Physics: Mechanics and Electromagnetism
• Quantum Mechanics
• Mathematical Methods
• Statistical Physics and Thermodynamics
• Biophysics, Optical Physics, Hydrodynamics, Plasma Physics, or Solid-State Physics

In partial fulfillment of the “mastery” requirement a student must successfully complete a minimum of 108 units of courses numbered 101 or above from the course schedule. In addition, 4 units of APh 110ab must also be completed. All courses must be passed with a grade of at least a C, except for courses offered only on a pass/fail basis. Students must also complete the degree progress report online upon completion of their courses.

Note: Any given class can only be used for one requirement category.

First year students are also required to take APh 110 ab, a two-term seminar course in which faculty review their research areas and ongoing research work in their group.

In addition to work in the classroom, students must complete a minimum of 27 units of laboratory or reading research through APh 200.

Students entering the program with advanced preparation may choose either to substitute more advanced courses in the topical areas shown or demonstrate competency by successfully passing both the midterm and final examinations. In such cases, students may petition the Applied Physics option representative to accept alternate subjects or areas. These changes should retain core applied physics knowledge, and maintain sufficient breadth. All such petitions must be submitted to the option representative and approved before the student registers for the course.

Coursework towards the Ph.D. degree in Applied Physics is normally completed within the first two years of graduate residency.

To fulfill the requirements for candidacy all students must pass an oral examination after completing their coursework. This examination must be taken before the beginning of the student’s third year in residence. Students will be expected to deliver a half-hour oral presentation giving a prospectus on their proposed thesis research. Following questions on the research prospectus, a more open-ended set of questions will be posed to the student by the committee members to test general proficiency in the five areas of pure and applied physics listed above. Students who fail the oral examination on their first attempt will be given additional guidelines for further study and an opportunity to retake the examination a second and final time if the committee so recommends. Students who fail the oral examination a second time cannot continue with doctoral studies leading to the Ph.D. Upon recommendation of the examining committee, however, a student may be granted a master’s degree. Annual approval of the applied physics option representative is necessary for registration beyond the third year of graduate residence if the student has not completed the candidacy examination.

Students who fulfill the requirements above will be recommended for candidacy to the doctoral program and a master’s degree (if applicable) in applied physics.

The candidate is to provide a draft copy of the completed thesis to the members of the examining committee (typically the same as the thesis committee) at least two weeks before the final oral examination. The date of the examination and the composition of the examining committee will not be approved by the dean of graduate studies until the thesis is submitted in completed form, i.e., ready for review by the dean, the members of the thesis committee, and the Graduate Office proofreader. Registration is required for the term in which the thesis defense is taken, but is not normally allowed beyond the last date of the term. For more information, please see the section entitled “Information for Graduate Students” in the Caltech Catalog.

The candidate shall undergo a final broad oral examination (thesis defense) in the field, to include the subspecialty represented by the thesis and the significance of its findings to the field. This oral examination will be administered at least two weeks after the doctoral thesis has been presented in final form so that the examining committee has sufficient time to review its content. This examination must be taken at least three weeks prior to the date on which the degree will be officially conferred.

The annual approval of the student’s Thesis Advisory Committee is necessary for registration beyond the twenty-fourth academic term of graduate residence at Caltech.

Graduate students majoring in other fields may elect a minor in applied physics. In addition to general Institute requirements, the student must complete, with a grade of C or higher, 81 units of courses in applied physics above the 100 level, excluding APh 200. The minor is also subject to the following conditions:

• Students cannot use courses required by their major option in fulfillment of this requirement.
• Students interested in a minor must receive prior approval from the option representative in applied physics, who will review and approve the proposed course of study.
• It is recommended that this course of study include advanced courses spanning different subfields of applied physics.