Monday, February 27, 2012

Why is condensed matter physics so hard for undergraduates?

The new semester has started here and I am helping teaching PHYS4030 Condensed Matter Physics. We basically cover some fraction of Ashcroft and Mermin. For some students, particularly those with weak backgrounds, this is a difficult course.
Some find it much harder than other courses. Why?
I can think of a few reasons of why CMP can be more demanding than other courses.

It requires a working knowledge of basic thermodynamics, statistical mechanics, kinetic theory, electromagnetism, and quantum mechanics. Weak students do o.k. in some subjects but poorly in others. Weak students do not remember much from previous courses and struggle to apply what they do learn in new contexts. Hence, CMP really exposes some of these weaknesses.
Furthermore, one has to understand how to integrate all this knowledge.

There is an emphasis on
  • orders of magnitude estimates 
  • making approximations
  • relating theory and experiment
On the other hand, for these same reasons motivated and well prepared students can find a condensed matter course very stimulating and interesting. Such a course also provides some skills (model building and testing, synthesis, estimates) which are useful in much broader contexts.

I welcome alternative thoughts.


  1. I generally agree. In most courses the concepts students need to learn are well defined, and there's a small number of equations to apply that cover just about everything. Condensed matter is completely different: nature is complicated, and we're trying to understand it. If a simple model isn't good enough to solve a particular problem, to be honest we need to design a more complicated model (ideally, a better simple model, but that is rarely possible), rather than just ignoring the problem in favour of a simpler one, like in EM, for instance.

  2. I struggled with solid state physics in the beginning of the semester. I am good enough in mathematics and Newtonian mechanics. Difficulty I faced was not in the content of the course but with the philosophy of solid state. Solid state is a course about theories and different situation to which one theory is suitable and other fails. That was the part I struggled with because all my earlier courses, though mathematically intense, did not have this 'different theories for different scenario' component in it. IMO, one of the ways to teach solid state could be: bombard the students with experiments and explain limitations of instruments when that experiment was conducted and then explain how some particular theory was best/simplest possible explanation at that time and even today that theory is good enough for some cases. And then build on this gradually.

  3. I suppose the real question for students is "How do I become a strong student? And how do I tell if I am a strong student?" This is not always as straight forward for us as it may seem.... Although, of course, condensed matter is both interesting and useful to study.