Physics 221AB

Quantum Mechanics

Fall 2020 and Spring 2021

University of California, Berkeley

Instructor:  Robert Littlejohn
Office:  449 Birge
Office Hours:   Fridays 11am-12
GSI:  Newton Cheng
GSI's email address:
Office Hours: Thursdays, 10-11

Lecture:  Internet/Online
Time:  TuTh 6:30-8pm
Discussion Section 101:   Wed 4-5, Online
Discussion Section 102:   Tue 11-12, Online
Recommended text:   Eugene D. Commins, Quantum Mechanics: An Experimentalist's Approach.
Final Exam:  Take Home; Available 5pm Monday, May 10; due 5pm Wednesday, May 12. Link to Final Exam

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 January 17, 2021, 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.

Prerequisites for 221B include graduate standing and Physics 221A or equivalent. "Graduate standing" implies a graduate student in the physics department, so it will be expected that you have sufficient background in subjects such as classical mechanics, statistical mechanics, electricity and magnetism and special relativity to do this course. Graduate students from other departments are advised that some knowledge of these subjects will be required for Physics 221B. Physics 221B will require a knowledge of special relativity at the level of Physics 209. Undergraduates wishing to take this course must make an application to Heather Makiharju in the physics department. I will then look at your transcript and make a recommendation. Admission to Physics 221 will also require approval of the head faculty advisor.

The grade will be based on homework and a final exam. The final exam will be take home. See above for details and the link.

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 will have to be sent electronically to the GSI. You will have to have some means (a scanner, a phone with a camera, an ipad, etc) to convert your homework to a pdf file that you can send to the GSI. The homework should be sent to the GSI's email account, which is with the subject line, "Physics 221B Homework".

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. You can use your free late homework for any purpose you wish (illness, travel, etc), 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.

Lecture notes will be available in one of two forms. By now typed up versions of lecture notes are available for almost all my lectures, but for those lectures without typed notes, I will usually try to supply hand-written notes. There are enough notes that usually 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. Homework must be submitted electronically, and you will have to have a means of scanning or converting your homework into electronic form (a pdf file). Send your homework to  

Interesting Movies.

Typed lecture notes are available for most lectures, not all.

Homework Solutions.


Links to web sites for other courses I have taught.

  • Physics 209, Fall 2002.
  • Physics 250, Fall 2015.