@@ -8,17 +8,23 @@ from common import draw_classic_axes, configure_plotting
configure_plotting()
```
# Lecture 2 – Free electron model
# Lecture 2A & 2B – Free electron model
_(based on chapters 3–4 of the book)_
Exercises 3.1, 3.3, 4.2, 4.5, 4.6, 4.7
Learning goals:
The learning goals of lecture 2A are to understand:
- the basics of 'Drude theory', describing electron motion in metals.
- how Drude theory predicts the generation of a 'Hall voltage' for electrons moving through a conductor in an electric and a magnetic field.
- central terms such as mobility and the Hall resistance.
The learning goals of lecture 2B are to understand:
- how to calculate the electron density of states in 1D, 2D, and 3D using the Sommerfeld free-electron model at T=0.
- how to express the total number and energy of particles in a system in terms of an integral over k-space.
- how to use the Fermi function to extend the previous two learning goals to finite T.
- how to calculate the electron contribution to the specific heat of a solid.
- central terms such as the Fermi energy, Fermi temperature, and Fermi wavevector.
- consider electrons as charged point particles travelling through a solid
- discuss Drude theory
- discuss the Hall experiment
- discuss specific heat of a solid based due to electrons
- introduce mobility, Hall resistance and the Fermi energy
### Drude theory
Ohm's law states that $V=IR=I\rho\frac{l}{A}$. In this lecture we will investigate where this law comes from. We will use the theory developed by Paul Drude in 1900, which is based on three assumptions:
