Structure and Dynamics Group

Corequisite:
Physics 142 (2014)

Announcements:

Please submit your PS1 and NB1 requirements here: Midterm Submission Form

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Please upload proof of satisfying corequisite here: Corequisite proof submission link

Notebook checklist items for previous semesters:

Week 13 (Dec 13)
Kittel ISSP Chapter 8, Semiconductors: Carriers and transport

Week 12 (Dec 6)
Kittel ISSP Chapter 8, Semiconductors

- Briefly discuss how band structure in semiconductors affect transport properties in the scattering time approximation.

Week 11 (Nov 29-Dec 1)
Kittel ISSP Chapter 7, Nearly free electrons

• Describe the Kronig-Penney model and summarize how it approximates the periodic potential in a crystal.
• Work on Problem Set 2, especially Problem II.
• Download Problem Set 2 here.

Week 10 (Nov 22-24)
Kittel ISSP Chapter 7, Energy bands I

• Briefly explain why the Bragg reflection of electron waves due to a periodic potential can cause band gaps to form at the boundaries of the Brillouin zone.
• Discuss how the presence or absence of band gaps give rise to insulating and conducting materials. 
• Consider a 1D crystal with lattice spacing a so that the potential also has period a. Use the Bloch theorem to write down the functional form of the eigenfunction solutions to the Schrodinger equation.  

Week 9 (Nov 15-17)
Kittel ISSP Chapter 6, A&M Chapters 1,3 Drude model for electron transport

• Provide a brief description of the Drude model of electron transport and the core assumptions needed for it to hold.
• Give the Drude model expression for Ohm's law and describe each of the quantities appearing in the Drude conductivity.
• Explain how a Hall effect experiment may be used to determine the charge and density of current carriers in a material.

Week 8 (Nov 8-10)
Kittel ISSP Chapter 6 Free electron gas

• Describe how a Fermi sphere forms in a 3D free electron gas at zero temperature due to Pauli exclusion.
• Obtain the Fermi energy of a free electron gas with density N/V.
• Make a sketch and describe the qualitative features of the Fermi distribution at low temperatures.
• Give a simple argument for why the specific heat of the electron gas is proportional to temperature at low temperatures. 

Week 7 (Oct 25-27)
Catch up week.

Week 6 (Oct 20)
Kittel ISSP Chapter 5 Crystal phonons

• Derive the leading temperature dependence of the phonon heat capacity in the Debye approximation at low temperatures (temperatures much lower than the Debye temperature).

Week 5 (Oct 9)
Kittel ISSP Chapter 4 Crystal vibrations

• Derive the dispersion relation for elastic waves in a one-dimensional monoatomic crystal.
• Explain why dispersion relations are typically reported only for wavevectors in the first Brillouin zone.
• Show how phonon momentum is accounted for in inelastic scattering processes.

Week 4 (Oct 4-6)
Kittel ISSP Chapter 3 Crystal binding and linear elastic response

• Summarize in a table the important features of the four types of crystal binding mechanisms discussed in class. You may use a sketch or cartoon to illustrate. Mention the quantum mechanical highlights.
• Briefly describe linear elastic response theory (one paragraph only). The theory can be summarized elegantly in a single tensor equation (and its inverse).