Advanced Statistical Physics

winter term 2021/2022
Lecturer: Prof. Tilman Enss
Link to LSF
7 participants

This advanced theory course builds on the statistical physics course (MKTP1) and introduces paradigmatic models of statistical physics and their critical properties near phase transitions.  In particular, we shall discuss the Heisenberg and O(N) vector models, the nonlinear sigma model, the XY model, the Sine-Gordon model, and the spherical model.  By computing their critical behavior, one can understand the phase transitions in many different systems in statistical physics, condensed matter physics and beyond, which belong to the same universality classes.  We will use field theoretic methods and introduce renormalization, epsilon expansion, and duality transformation.

Contents

  1. Landau theory and O(N) vector model
  2. Renormalization group and universality
  3. Nonlinear sigma model and epsilon expansion
  4. Topological excitations in the XY and Sine-Gordon models and the Kosterlitz-Thouless transition
  5. Spherical model and quantum phase transitions
  6. Disordered systems
  7. Random walks
  8. Critical dynamics

Timeline

2021-10-18: no tutorial (tutorial starts in the second week)

2021-10-19: Lecture 1, Landau theory and mean field ansatz

2021-10-21: Lecutre 2, Fluctuations beyond mean field

2021-10-25: Tutorial 1, Correlations

2021-10-26: Lecture 3, O(N) and phi^4 models; scaling and renormalization

2021-10-28: Lecture 4, Renormalization group equations

2021-11-01: no tutorial (public holiday)

2021-11-02: Lecture 5, Relevance and universality

2021-11-04: Lecture 6, Multiple fixed points

2021-11-08: Tutorial 2, Ginzburg criterion

2021-11-09: Lecture 7, Nonlinear sigma model

2021-11-11: Lecture 8, Renormalization of the NLSM

2021-11-15: Tutorial 3, Flow equations

2021-11-16: Lecture 9, XY model and spin waves

2021-11-18: Lecture 10, Vortices and Coulomb gas

2021-11-22: Tutorial 4, Limit cycles

2021-11-23: Lecture 11, Sine-Gordon model

2021-11-25: Lecture 12, BKT transition

2021-11-29: Tutorial 5, Duality

2021-11-30: Lecture 13, Quantum phase transitions

2021-12-02: Lecture 14, Random systems

2021-12-06: no tutorial (postponed)

2021-12-07: Lecture 15 (video), Random systems: renormalization

2021-12-09: Lecture 16, Spin glasses (up to page 6-12)

2021-12-13: Tutorial 6, Quantum scaling

2021-12-14: Lecture 17, Replica symmetry breaking (up to page 6-18)

2021-12-16: Lecture 18, Neural networks and Anderson localization (up to page 6-23)

2021-12-20: Tutorial 7, RKKY

2021-12-21: Lecture 19, Random walks (up to page 7-5)

Christmas break

2022-01-10: Tutorial 8, Percolation (example code)

2022-01-11: Lecture 20, Random walks (up to page 7-9)

2022-01-13: Lecture 21, Fluctuation-dissipation relation and Langevin equation (up to page 8-4)

2022-01-17: Tutorial 9, Random walks

2022-01-18: Lecture 22, Dynamical scaling and Master equation (up to page 8-9)

2022-01-20: Lecture 23, Response functional and directed percolation (up to page 8-14)

2022-01-24: Tutorial 10, Stochastic dynamics

2022-01-25: Lecture 24, Fokker-Planck equation and approach to equilibrium (up to page 8-19)

2022-02-08: voluntary Question & Answer session in preparation for the exam

2022-02-15: written exam

Literature

As an introduction, the lecture notes by Mudry are recommended; Mudry chapter 1 introduces the field theoretical language.
For starters:

  • Cardy, Scaling and Renormalization in Statistical Physics, Cambridge University Press (1996)
  • Mudry, Lecture Notes on Field Theory in Condensed Matter Physics, World Scientific (2014)

Further reading:

  • Altland and Simons, Condensed Matter Field Theory, Cambridge University Press (2010)
  • Kadanoff, Statistical Physics: statics, dynamics and renormalization, World Scientific (2000)
  • Negele and Orland, Quantum Many-Particle Systems, Addison-Wesley (1988)
  • Stein and Newman, Spin Glasses and Complexity, Princeton University Press (2013)
  • Zinn-Justin, Phase Transitions and Renormalization Group, Oxford University Press (2007)

Practice groups

  • Group 1 (T. Enss)
    7 participants
    Philos.-weg 12 / R 105, Mon 14:15 - 16:00
up
Advanced Statistical Physics
winter term 2021/2022
T. Enss
Link zum LSF
7 participants
calendar