“The solution of the difficulty is that the two mental pictures which experiment leads us to form- the one of the particles, the other of the waves- are both incomplete and have only the validity of analogies which are accurate in limiting cases.” -Werner Heisenberg

Welcome to the website for the Johns Hopkins undergraduate quantum mechanics course.  From here, you can get contact information, download assignments and solutions and check for announcements.  Many links on this page are to PDF files.  To view them, you can download Acrobat Reader for free.

Professor Chien’s lectures are Monday, Wednesday, Friday, 9-9:50 am, in Bloomberg 361.

Logan’s conference section is Tuesday, 1:30-2:20 pm, in Bloomberg 464.

Sometimes, section and class will switch places; this will be announced in advance in class.

Course Description

This course is the first semester of two giving an introduction of quantum mechanics, beginning with non-commuting observables, angular momentum, two-state systems, time evolution, the wave equation in one dimension, and the simple harmonic oscillator.

PDF Document: Course Syllabus

Required Textbooks:

  1. J. S. Townsend, A Modern Approach to Quantum Mechanics, University Science Books (California) 2012.


We will go over new concepts and provide examples that help you solve the upcoming problem assignments. Read the assigned text in advance, especially the examples. Read again afterwards and do some problems for optimal comprehension. Active participation in the lectures with questions and comments is strongly encouraged.


Conferences focus on improving your problem solving skills. They are also a good opportunity to ask questions.


Solving problems is how you learn physics. There will be a weekly assignment assigned every Monday, due the Monday of the following week. The assignments are due at or before section on the due date and late homework will generally not be accepted. Solution sets will be available in conference or on the course website shortly after the due date.


University Policy: The strength of the university depends on academic and personal integrity. In this course, you must be honest and truthful. Ethical violations include cheating on exams, plagiarism, reuse of assignments, improper use of the Internet and electronic devices, unauthorized collaboration, alteration of graded assignments, forgery and falsification, lying, facilitating academic dishonesty, and unfair competition.

Doing the homework is crucial to learning the material is this class. Working together can be useful and productive, and hence is not forbidden, provided that all parties put in equal effort. It is strongly recommended that you not collaborate until you have each thought about and tried the homework. Outright copying of each other’s homework is not allowed. If you do not put this effort in on your own, you will not learn the material, and it will be readily apparent on the exams.


Homework: 25%
Midterm: 25%
Final Exam: 50%