QUANTUM PHYSICS

PHY 401- Fall 2008

University of Maryland, College Park

PHY 401- Fall 2008

University of Maryland, College Park

**Instructor**: Prof.
Paulo Bedaque

*bedaque@umd.edu
*

tcliu@umd.edu

^{rd} and 5^{th})
will be taught by Michael Buchoff and Aleksey Cherman. The regular instructor
(Paulo Bedaque) will be back on Monday, September 8^{th})

Lecture hours: Mondays and Fridays, 10:00 am – 10:50am

Wednesdays, 10:00 am – 11:50am

Office hours: Mondays and Fridays, 10:50 am – 11:50am or other times previously arranged

Textbook: We will
not follow closely any book but the closest one is "*Introduction to Quantum Mechanics", *by* David J. Griffiths* (any edition will do). Many other texts, most
of them found in the library, can also be very useful. You are encouraged to
explore. For the historical part (black body radiation, Bohr atom, ...) one recommendation is "Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles**" **by
R. Eisberg and R. Resnick. Keep inmind that Eisberg&Resnick cover
MUCH more material, in depth and breadth, that we will. You will also
probably enjoy reading the cartoon book "Introducing Quantum Theory" by J. P. McEvoy. Don't let it fool you, this book has content ! it is an ideal reading for before the class starts.

I noticed in that
many (most?) students in the previous
years had difficulties in the class due to improper mathematical
background as opposed to the inherent difficult of the new material. As
a remedy, the first two lectures will be devoted to 1) complex numbers
and 2)
differential equations. The material of the “complex
number” lecture is well
described in chapter 3 of the free (and excellent) textbook
“Mathematical Tools
for Physics”, by James Nearing, which can be downloaded from this
site.Also, I wrote a very short summary (ps, pdf) you may find useful. What we will need about differential equations before the class starts
is very minimal and there is also a summary (ps, pdf) I wrote. As the class
progresses more mathematics will be needed and I’ll discuss them during the
semester. In particular, a good knowledge of linear algebra, both in its
abstract and computational aspects, is essential for the full understanding of
quantum mechanics. Again, Nearing’s book (chapters 6 and 7) is a good place to
start.

Grading policy: There will be three tests, each one worth 30% of the final grade. The remaining 10% will be determined by the periodic homework. Possible make up tests can be offered only to students with a valid health reason (with doctor’s note) and should be arranged as soon as possible. Students who cannot attend a test due to religious reasons should contact the instructor as soon as possible to discuss an alternative. Grades will be posted on Blackboard.

Honor code: Students are encouraged to discuss the homework among themselves but they should be prepared to explain every step to the instructor, if asked. No collaboration, notes, books or calculators are allowed during the tests.

Homework

homework 2 , Mathematica code solution, solution to the numerical part

homework_3 solution (courtesy of T. C. Liu)

Tests

First midterm: 1st part October 6th, 10:00 am to 10:50 am, 2nd part October 8th 10:00 am to 10:50 am solution

Second midterm: November 26th, 10:00am to 11:50am solution

Final: December 20th, 8:00 am to 10:00 am at Physics Building 1201 final solution

Lecture Notes

Notes on the historical development of quantum mechanics (short summary).

And some more on the Bohr atom and de broglie hypothesis.

two incredibly short summaries of quantum mechanics: one in the old notation and another with bras and kets.

And some more on the Bohr atom and de broglie hypothesis.

two incredibly short summaries of quantum mechanics: one in the old notation and another with bras and kets.

Interesting links

Potential barriers

Movies showing wave packets colliding with walls, etc..

Applet showing a wave packet tunneling through a barrier.

Blackbody radiation

You can buy your own blackbody here.

A nice figure of the blackbody spectrum.

The Universe as a blackbody: the spectrum from COBE and the tiny variations of the temperature with the direction in space. More about the COBE sattelite.

Even NASA scientists know that holes are really dark, even in Mars.

Photoelectric effect

An applet that simulates the photoelectric effect. Try varying the different handles and predicting the outcome !

Founding Fathers

Video of the Solvay Conference of 1927 showing all the Quantum Mechanics Founding Fathers during their breaks. Eisntein And Schroedinger did not seem happy about all that talk about probabilities.

Syllabus

One change in relation to the previous years is that I will not start discussing the history of how quantum mechanics was discovered/invented. But I plan to discuss that in the middle of the semester. Our tentative syllabus is

- Principles of Quantum Mechanics

Non-determinism in quantum mechanics: wave function and its statistical interpretation (with a quick review of probabilities); Schroedinger equation; Momentum distribution and a first look at the uncertainty principle

- Stationary states

Infinite square well: transmission and reflection

Harmonic oscillator

Free particle

Delta function potential

Finite square well: tunneling

- The creation of Quantum Mechanics

Blackbody radiation

Compton effect

Photoelectric effect

Bohr atom

- The formalism of Quantum mechanics

Review of linear algebra; Dirac notation

Observables and operators; Eigenfunctions and eigenvlaues

Generalized statistical interpretation

Two-level systems

- Quantum Mechanics in three dimensions

Schroedinger equation in spherical coordinates

Angular momentum

Hydrogen atom

Spin

- Multi-particle systems

Bosons and fermions; Applications to atoms, nuclei, solids, …