6.728  Appl Quantum & Statistical Phys

REMINDER: Final Exam 9am-12pm at 32-141 - 3 Sheets of Formula Allowed

Dear class,

Just a friendly reminder that the finals will be held tomorrow at 32-141 from 9am-12pm.

You can bring Quiz I and Quiz II formula sheet, along with
one more formula sheet (1 page) for the final.

All the best!

adrian

Announced on 20 December 2011  7:28  p.m. by YiXiang Yeng

Extra Office Hours

Dear class,

I will hold extra office hours in my office (NE47-579) from 9am to 12pm on Monday. Please call the reception to allow your access to the floor.

Cheers,
adrian

Announced on 16 December 2011  10:36  p.m. by YiXiang Yeng

Clarification on 2007 Finals: Problem 1(c) and 3(a)

Dear class,

I've asked Prof. Hagelstein, and here are the answers I promised:

For 1(c), the best approach is to say that the continuum limit is appropriate for large l, so we can approximate the energy as

E(l) = hbar^2 l^2 / 2 M R^2

The density of states in terms of l follows as

g(E) = 2l*dl/dE = (hbar^2 l / M R^2)^(-1)

Then you have to solve for l in terms of E.

For 3(a), your question is a nontrivial one. In class and I think in the book we had argued that the photon has spin 1. Circularly polarized light traveling in the z-direction
has an angular momentum of one unit of hbar per photon angular momentum in the z-direction, as is known from theory and has been measured experimentally.

I guess that the big question is how the students are supposed to have known it or figured it out. The logic at the time was that the hydrogen atom would gain or lose
one unit of angular momentum for a radiative transition, so if a lot of photons with the same circular polarization were absorbed probably you would expect the disk to gain that many units of angular momentum.

cheers,
adrian

Announced on 16 December 2011  10:34  p.m. by YiXiang Yeng

Extra Office Hours + No Tutorials This Week + Final Exam Review

Dear class,

We've completed the problem sets and there will be no tutorials this week.

Instead, extra office hours will be scheduled before finals. Time and place to be determined.

Also, tomorrow will be the last lecture. On Wednesday, Prof. Hagelstein will not be around. I will go through the problems in previous years finals for that session. Please try to attempt the questions to facilitate discussion.

cheers,
adrian

Announced on 11 December 2011  10:22  p.m. by YiXiang Yeng

Past Years Finals Uploaded

Dear class,

2007 and 2009 Finals have been uploaded. As for the schedule of this year's finals, you can check it out at http://web.mit.edu/registrar/classrooms/exams/finals/2012FA_finals_by_subject.html#6

As of today, it is scheduled for 9am Dec 21st, at 32-141.

cheers,
adrian

Announced on 09 December 2011  5:22  p.m. by YiXiang Yeng