Physics of Disordered Systems
Time and location: Time: Fridays, 14:15-15:45; Location: F3M1
Lecturers: János Török and Gergely Zaránd
Lectures will be given in English, but questions can also be asked in Hungarian, and the language of the exam/problem set can also be chosen to be Hungarian.
Goal: Disorder is present everywhere around us, and it leads to fascinating phenomena. This course is supposed to cover some of these subjects, including Anderson's localization theory, Coulomb glasses and spin glasses, hysteresis or percolation, Griffith phases, just to name a few.
Prerequisites: Quantum mechanics, intermediate level solid state physics, statistical physics.
Subjects to be covered:
Polimers, fractals, liquids, glasses, quasicrystals, amorphous metals, granular materials. Percolation.
Disordered magnetic systems:
Hysteresis, memory effects, and Preisach model. Domain wall motion: mean field theory, Barkhausen noise.
Disordered ferromagnets and Griffith phase. Frustrated spin systems and spin glasses: phyenomenology, Sherrington-Kirpatrick model, TAP equations. Replicas, and replica symmetry breaking. Dropplet theory.
Disordered semiconductors and impurity bands. Locaization transition and Anderson's theory. The scaling theory of localization. The Coulomb glass. Crytical wave function and multifractal properties. Quantum Hall effect.
The Bose glass. Fisher scaling and the strong disorder fixed point.
Students can get a mark in three different ways:
by passing an oral exam,
by solving problem sets
or by writing (in English or in Hungarian) a term paper (i. e., a 10-15 pages written summary based upon some research paper, related to the course).
For the last two options (term paper / problem set), you must pass the "substantial presence test", i.e., cannot miss more than 3 lectures. Of course, to pass an oral exam, no substantial presence at the lectures is requested. Just come and try!
Subjects of oreal exam: TO BE SPECIFIED
Problem set: TO BE COMPLETED
Term Papers: The term paper should be an approximately 15-20 (standard latex preprint) pages presentation on the subject. In the first half of it, you should review basic knowledge, and put the paper in contex, introduce basic notions. Here you should just include material that you learned at class. In the second part of your work, you should present what you understood from the paper(s) assigned. You do not need to understand everything but all what you present should be clear and thought through. You can also consult some of the references given in the papers, but do not try to read everything... You can write the term paper in Hungarian or in English.
If you decide to write a term paper, you can pick one of the following papers:
· Ali Yazdani's paper on GaMnAs: Richardella et al, Science 327, 665-669 (2010) (arxiv.org:1002.1037);
· Aspect's work on 3D localization: F. Jendrzejewski et al, Nature Physics 8, 398 (2012); (or : Aspect_nphys2256_localization.pdf);
· Mean field model for Coulomb glass dynamics: Amir, Oreg, Imry PRB77, 165207 (2008); PRL103, 126403 (2009).
· Multifractal analysis, Römer's work: PRB78 195106 (2008), PRL102 106406 (2009).
Some supplemental material:
Some literature (incomplete):