Fall 2018

Class meets MWF 1:30-2:20PM and M 2:30-3:20 in Wean Hall 7423

Website http://euler.phys.cmu.edu/widom/teaching/33-783

Professor Michael Widom, Office 6305 Wean Hall

e-mail: widom@cmu.edu, Phone: 412-268-7645

Office Hours: Any time I'm not busy (by appointment if desired)

**What you will learn:** This course presents an introduction to the physics of solid state materials, with an emphasis on traditional bulk crystalline materials but with occasional examples drawn from modern topics such as quantum wells, graphene, etc. Topics will be broadly separated into two segments. First, in the **physics of the solid continuum**, you will apply simple classical or quantum mechanical models to examine electronic, magnetic, vibrational, optical and thermal properties of matter. Next, in the **physics of the crystal lattice** you will learn diffraction techniques for probing the structure and symmetries of crystals and understand how diffraction of phonons and electrons create band structures and enable technologies such as semiconductor devices.

**What you should know:** This course will be fast-paced. Prior
familiarity with quantum mechanics is assumed at the graduate level of
33-755/756, and statistical mechanics/thermodynamics at the graduate
level of 33-765. Students with less preparation (e.g. quantum mechanics
at the undergraduate level of 33-445/446 and statistical mechanics at
the level of 33-341/342) should consider taking the undergraduate
Solid State Physics course 33-448 instead.

**Books:** Several excellent books are available on reserve in the E&S library. Just ask at the desk.

1. Ashcroft and Mermin, Solid State Physics, QC176.A83

2. Simon, The Oxford Solid State Basics, e-book http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=598413

3. Kittel, Introduction to Solid State Physics (8th edition), QC176.K5 2005

4. Goodstein, States of Matter, QC173.3.G66

Ashcroft and Mermin is the classic graduate-level textbook for the field and an important reference book to keep on hand. Simon is similar to Ashcroft and Mermin in its outline, but with updated and slimmed-down content presented at an advanced undergraduate level. These two books will be the primary texts for the course, and the source of most assigned homework problems. Kittel is the classic undergraduate-level textbook and presents the material in an alternative fashion. Goodstein has excellent background material on thermal physics, a chapter on solids offering a nice "thumbnail sketch" of this course, and a detailed chapter on superconductivity.

**Grading:** Letter grades will be based on homework, midterm exams and a final exam. The first midterm exam is scheduled for Friday, Oct. 5. Homework assignments (click here) will be supplemented with reading of articles from the original literature. Students will lead and participate in discussion of these articles.

**Course Outline:**

Note this outline is only approximate. Actual class coverage can be found here.

**Physics of the solid continuum**- Free electron models (Drude/Sommerfeld)
- DC and AC conductivity, classical model
- Electron gas density of states and Fermi surface
- Magnetoconductance
- Hall effect (classical and quantum)
- Heat capacity
- Thermal conductivity (Wiedemann-Franz law)
- Pauli Paramganetism

- Elasticity
- Continuum elasticity
- Classical modes and quantized phonons
- Heat capacity
- Thermal conductivity
- Raman and Brillouin scattering

- Electrons and phonons - superconductivity

- Free electron models (Drude/Sommerfeld)
**Physics of the crystal lattice**- Crystal structure
- Crystal symmetries and space groups
- Crystal structure (lattice with basis)
- Diffraction of x-rays and neutrons (Bragg and Laue)
- Brillouin zones

- Dispersion relations
- Phonon dispersion relations
- Nearly free electrons
- Peierls instability
- Electron tight-binding model
- Graphene
- Hubbard model of magnetism

- Metals and semiconductors
- Fermi surfaces of metals
- Electrons and holes
- Semiconductors
- Solid state devices

- Crystal structure