### 2020　Statistical Mechanics II(Exercise) A

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Instructor(s)
Takahashi Kazutaka
Course component(s)
Exercise    (ZOOM)
Day/Period(Room No.)
Thr7-8(H112)
Group
A
Course number
PHY.S322
Credits
1
2020
Offered quarter
2Q
Syllabus updated
2020/9/18
Lecture notes updated
-
Language used
Japanese
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### Course description and aims

The situation that the number of particles of a physical system varies is described by the grand canonical ensemble, which takes the chemical potential as a parameter. The grand partition function is introduced as a tool of calculation. Many particle quantum mechanics for Bose and Fermi particles is explained. The statistical mechanics for Bose particle and that for Fermi particle are quite different in low temperature and high density (Bose condensation, Fermi degeneracy). Basic exercises on phase transition, critical phenomena, non-equilibrium phenomena are prepared.

This exercise class aims to develop students' ability to solve basic problems on statistical mechanics when the number of particles varies, quantum statistical mechanics and theory of phase transition.

### Student learning outcomes

This course facilitates students' understanding and ability of calculation of grand canonical ensemble, statistical mechanics of quantum ideal gases, physical phenomena originated from difference between Fermi and Bose particles, phase transition, critical phenomena, non-equilibrium phenomena.

### Keywords

grand canonical ensemble, chemical potential, quantum ideal gases, Bose distribution, Fermi distribution, Bose condensation, Fermi degeneracy, super-fluid transition of Helium 4, specific heat of metals, phase transition, critical phenomena, critical exponent, mean field approximation, transfer matrix method, Ising model

### Competencies that will be developed

 ✔ Specialist skills Intercultural skills Communication skills ✔ Critical thinking skills ✔ Practical and/or problem-solving skills

### Class flow

Exercise materials are distributed in advance. Students are expected to solve exercises at home and to present answers on blackboard. Presented answers are discussed.

### Course schedule/Required learning

Course schedule Required learning
Class 1 grand canonical ensemble I (review of thermodynamics, basics of granduanonical ensemble) In grand canonical ensemble, particle number varies, whereas chemical potential is specified.
Class 2 grand canonical ensemble II (grand partition function, application of grand canonical ensemble) Grand partition function is the tool for calculation in the theory of grand canonical ensemble.
Class 3 statistical mechanics of quantum ideal gases I (many particle quantum mechanics) In many particle quantum mechanics, any state has a definite parity for two particle exchange based on statistics of the particle.
Class 4 statistical mechanics of quantum ideal gases I (ideal Fermi case, Sommerfeld expansion, specific heat and magnetic susceptivity of ideal Fermi gas) A strongly degenerate Fermi system can be analyzed by Sommerfeld expansion. Specific head and magnetics susceptivity of metals can be explained by Sommerfeld expansion.
Class 5 statistical mechanics of quantum ideal gases II (ideal Bose case, black body radiation, introduction of Bose condensation) When ideal Bose case is placed in low temperature enough, macroscopic number of particles condense in the microscopic ground state.
Class 6 phase transition and critical phenomena I (phase and phase transition, first order transition, second order transition) Distinction of phases in a phase transition is described by the corresponding order parameter.
Class 7 phase transition and critical phenomena II (What is critical phenomena?, critical exponent, mean field approximation, Landau theory) Critical phenomena in a phase transition are described by universal critical exponents irrespective of details of the system. The first step to analyze phase transition in a model is to apply the mean field approximation to it.

### Out-of-Class Study Time (Preparation and Review)

To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.

None.

None.

### Assessment criteria and methods

Based on blackboard presentation, report and examination.

### Related courses

• ZUB.S310 ： Thermodynamics and Statistical Mechanics II
• ZUB.S217 ： Exercises in Thermodynamics and Statistical Mechanics I

### Prerequisites (i.e., required knowledge, skills, courses, etc.)

Students are expected to have learned Thermodynamics and Statistical Mechanics I and Exercises in Thermodynamics and Statistical Mechanics I.