Part 1 (Free Electron Theory) Flashcards
What happens in a fermi wave vector?
For N electrons, lowest energy N/2 states will be filled
Fill states up to kF (fermi wave vector)
Each state occupies a cube in k-space
Where do states fill up to?
The fermi wave vector or the fermi energy
What is the Fermi Surface?
Surface of constant energy separating filled and empty states
What the density of states?
States per unit energy range
Which electrons are capable of being excited by small energies?
Electrons close to the Fermi level
Where do electrons’ magnetic moments arise from?
From spin
What does the application of a field do?
Shifts spin up and spin down DoS against each other
What does Pauli paramagnetism include?
Temperature independent susceptibility
What does a magnetic field do electrons?
Deflects electrons sideways
sets up electric field
What does an electric field do to electron?
Applies a force of -eE to electrons (shifts fermi sphere)
What gives a steady state with constant shift in k-space?
Constant drift away from origin offset by scattering of electrons to dissipate energy
When does scattering occur?
At imperfections in the crystal lattice
What does resistivity of a material depend on?
Whether sample is clean or dirty
What is Wiedemann-Franz law?
The ratio of the electric contribution of the thermal conductivity to the electrical conductivity
