Lecture Notes on Equilibrium Statistical Mechanics (Physics 211)#
UNIVERSITY OF CALIFORNIA, BERKELEY DEPARTMENT OF PHYSICS
Instructor: Prof. Oskar Hallatschek (he/his), Office: 408D Stanley Hall, Email: ohallats@berkeley.edu
The following lecture notes are designed to complement the Berkeley Physics course 211 material covered in the spring of 2025. Special thanks to Mike Zalatel and Dunghai Lee for their invaluable lecture notes, which have partially influenced my own.
The course structure is adapted and reordered from Kardar’s textbook.
Probability & information entropy
Kardar 2, Arovas 1
Fundamentals of thermodynamics via molecular perspective - ensemble theory
Kardar 4, Arovas 4
Non-equilibrium Fluctuation theorems
lecture notes
Dynamics of interacting particles
Kardar 5, Arovas 6
Monte Carlo, Debye-Hueckel, Diffusion
lecture notes
Study of Hamiltonian dynamics and ergodicity
Arovas 3, Kardar 3.1, 3.2
Quantum statistical mechanics
Kardar 6+7, Arovas 5
Exploration of mean field and Landau theory
Arovas 7
Important Notes:
Undergraduate level thermodynamics, a prerequisite for this course, will not be covered. Students are encouraged to review this material independently if needed.
A brief overview of probabilistic reasoning will be provided (in class and discussions); however, extensive time cannot be dedicated to this. Students are advised to actively review these concepts on their own. (Kardar 2!!)
The syllabus is subject to modifications, aiming to incorporate modern topics relevant to current research in active matter, (quantum) information theory, and machine learning.
Syllabus Updates: The syllabus will be updated throughout the course.
- Course Information
- Quick Summary of Statistical Mechanics
- Probability, energy and entropy
- Entropy and information
- Classical statistical mechanics
- Meaning of equilibrium
- Equipartition
- When a Macrostate is a Microstate
- Gibbs entropy / Partition Function / Free energy
- Trading conserved quantities between reservoir and system // External forces
- Molecular Dynamics Simulation of Thermalization
- Two standard examples for a system coupled to an external field
- Section 1: Ising Paramagnet
- Section 2: Freely Jointed Chain in an External Force Field
- Section 2: Freely Jointed Chain in an External Force Field
- Spontaneous Reactions
- Non-equilibrium fluctuation theorems
- Chemical reactions
- Statistical mechanics with interactions - Ising models
- Finite dimensional Ising models
- Existence of a phase transition in the 2D Ising model
- Variational Method
- Interacting Gases
- Variational treatment of a gas and the van der Waals equation of state
- Monte Carlo, Markov Chains, and the Metropolis Algorithm
- Debye-Hückel theory - charge screening
- Brownian Motion as a Free Energy Minimizing Process
- Coarse-graining and Ergodic Theory
- When does quantum mechanics make a difference?
- Gapless quantum matter: phonons + Debye model Coldstone’s Theorem
- Debye Model.