Physics 221B

Quantum Mechanics

Spring 2012

University of California, Berkeley

Instructor:  Robert Littlejohn
Office:  449 Birge
Office Hours:   Friday 1-2
Telephone:  642-1229
TA:  Austin Hedeman, Office Hours 3-4 Thu, Room 443 Birge

Lecture:  9 Lewis
Time:  MWF 9-10
Discussion Section 1:   Wed 2-3, 75 Evans (probably to be canceled)
Discussion Section 2:   Tu 4-5, 105 Lattimer (probably to be canceled)
Recommended text:   J. J. Sakurai, Advanced Quantum Mechanics.

The 221A web site for Fall 2011 is here.

Final Exam:  Oral, Monday, May 7 to Friday, May 11

Organization and Logistics

The email address for this course is   Use this to send me emails if you have any questions etc. Also, I maintain an email mailing list for the course, and use it to send out announcements, corrections to homework assignments, etc back to you. If you received an email from me on Tuesday, January 16, then you are on the email mailing list and do not need to do anything. If you did not receive an email from me, then send an email to the course email address (above) and ask to be added to the mailing list (you do not need to be enrolled). If you drop the course or don't want to receive any more announcements, send an email to this address with a request to be dropped. 

The course web site (this site) will be used to post lecture notes, special notes, homework assignments, and homework solutions.

There will be no discussion section during the first week. I will probably cancel both official discussion sections and hold ours in the Panic room, Thursdays 2-3, just as last semester.

Prerequisites for this course include graduate standing, Physics 221A, and a background in special relativity such as taught in Physics 209. Students who do not have this background are required to get instructor's approval before enrolling. In particular, this applies to all undergraduates wishing to take the course.

The grade will be based on homework and a final exam. I am planning an oral final exam this semeter. Later I will ask students to sign up for time slots for the oral during the week of May 7 to 11.

Weekly homework assignments will be made available on this web site (usually) by Saturday of each week, and will be due at 5pm on Friday afternoon of the following week. Homework should be turned in in the 221B homework box in 251 LeConte (the reading room). I'm scheduling the discussion section on Thursday, so it will be one day before the homework is due (on Friday).

Late homeworks will be accepted up to one week late at 50% credit. Homeworks more than one week late will not be accepted. Please do not ask the reader to take late homeworks. Exception: Each student is allowed one free late homework (up to one week late) during the semester, no questions asked.

Students are encouraged to work together on homework, and to trade ideas. There is no better way to learn. However, it is expected that the work you turn in is your own work in your own words. It is not legal just to copy someone else's solutions. It is also strictly illegal to look at or use solutions from any previous version of this course from earlier years. You can't find those solutions anyway without going to some trouble.

The text for the course, Modern Quantum Mechanics, by J. J. Sakurai, was chosen because of its good selection of topics, because of the generally deep perspective it takes in developing the subject, and because of his good physical perspective. Unfortunately, the explanations in the book are often poor and sometimes wrong; this seems to be due to the fact that Sakurai died before he could put his book into order. (His other book, Advanced Quantum Mechanics, which we will use in Physics 221B, is much better.) To make up for these deficiencies, most weeks there will be lecture notes made available which will supplement the readings from the text.

The content of Physics 221A is mostly a review of undergraduate quantum mechanics, presented from a deeper point of view and with a different emphasis. Some new topics are also presented. Physics 221B presents much new material, including an introduction to field theory and relativistic quantum mechanics. The course will have an emphasis on atomic physics that gradually turns into particle physics.

Movies for some of the lectures are available due to the efforts of Eric Corsini.

Lecture notes will be available in one of two forms. For some lectures I have typed-up notes. For those lectures without typed notes, I will usually try to supply hand-written notes, although I don't guarantee how closely they will follow the actual lectures. Nevertheless, it should be possible to get by without taking notes in class. Do not be afraid to interrupt the lecture to ask questions.

Homework assignments will normally be made available on this web site by Friday or Saturday of each week, and will be due at 5pm on Friday of the following week in the 221A homework box in 251 LeConte (the reading room). 

Typed lecture notes are available for some lectures, not others.

The Final (Oral) Exam will be given during the week of May 7-12. The exam will last one hour and twenty minutes. Please choose a time slot during that week, and send me an email with your choice. Time slots will be allocated on a first-come-first-serve basis.

I will try to break the 80-minute exam period into four sessions of twenty minutes, each focusing on a topic covered in the semester. However, once a line of questioning is started, it can go anywhere within the material covered during the semester. Oral exams tend to test physical understanding first and computational details second, so let that guide you when you study.

However, if you choose (it is up to you), you can select one topic to specialize in for one of the four 20-minute periods. This will allow you to put your best foot forward. The topics in which you can specialize must be taken from the following:

Time-dependent perturbation theory, with applications; scattering theory; quantization of the electromagnetic field; emission and absorption of radiation; the Dirac equation; relativistic electron-photon processes in QED. I may add to the list of topics as the semester proceeds, but this is the basic list.

You may also bring along a friend, for company and moral support, but it cannot be someone who is scheduled to take the oral exam after you. After you have taken your oral exam, you must not discuss it with anyone in the class before all the exams are finished.

The grades will be on a scale from 1 to 7, but no grades will be assigned until all the exams are completed.

Homework Solutions for Fall 2011.


Links to web sites for other courses I have taught.

  • Physics 209, Fall 2002.
  • Physics 250, Fall 2008.

  • Extra Notes.