Physics 223B (Winter 2016)

Physics 223B, Graduate Condensed Matter Physics, Winter 2016


Prof. Matthew Fisher

Email: ;

Office: 2305 Kohn Hall

Lectures: Monday, Wednesday 9:30-10:45 am, Phelps 2514

Office Hours: Monday 2:00-3:30, plus to be arranged

Find the course web site thru my personal web site:

Grader: Katie Hyatt


Office: 6218 Broida Hall


Condensed Matter Physics: Condensed matter physics is an enormously broad field, arguably "larger" than all of the other subfields of physics combined.  Even in a full year sequence, it is impossible to even touch upon the myriad of phenomena.  To complement 223A, in 223B I will try to focus on collective (i.e. emergent) phenomena, in which the whole is more than the sum of the parts.  Important concepts will include symmetry breaking, order parameters, collective excitations and other.  My intention is to focus predominantly on 2 broad areas, (i) Quantum Magnetism of Insulating Crystals, and (ii) Superconductivity -  phenomenology plus BCS theory.  See a tentative syllabus below, subject to change.  If time permits we might be able to touch upon superfluididity of many-boson atoms (e.g. 4-He). 

Textbooks: No official text book, since I will not follow any one book. On magnetism, some books are (i) Ashcroft and Mermin, (ii) Interacting Electrons and quantum magnetism by A. Auerbach, and (iii) Electron Correlations and Magnetism by P. Fazekas. The book by TInkham, Introduction to Superconductivity, is quite accessible, and fairly complete.

Homework: Roughly 5 homeworks throughout the quarter, available on the course web site.  Homework solutions also posted online.  You are encouraged to work together on the homeworks.

Exams:  None. Unless requested!


Help/feedback: In addition to my office hours, I would be happy to schedule a mutually convenient time to chat about homework or other topics (best arranged by e-mail).  I would greatly appreciate feedback on any aspect of the course, anytime throughout the quarter.


SYLLABUS: (tentative)

Magnetism of Insulating Crystals:

  • Single atoms/ion, Hunds rules, intraatomic exchange
  • Magnetic interactions, interatomic exchange, Heisenberg model
  • Collective Magnetic Phenomena overview: magnetic ordering, symmetry breaking
  • Ferromagnetism; Ground states, spin-wave theory, domain walls and hysteresis
  • Antiferromagnetism; Ground states, spin-wave theory for magnons, expermental probes - NMR and neutrons
  • Other quantum states; Valence Bond crystals, spin liquids, topological ordering


  • Experimental Phenomenology; Meissner effect, Type I, Type II, ...
  • Ginzburg-Landau theory
  • BCS theory; ground states, excitations, thermodynamics