Introduction
Why Condensed Matter Physics?
Condensed matter physics is the study of how quantum mechanics governs the collective behavior of enormous numbers of particles — the atoms, electrons, and phonons that make up solids and liquids. It is the largest branch of physics, and the most practically important: transistors, superconductors, LEDs, MRI machines, and hard drives all rest on condensed matter foundations.
This course implements the core equations of condensed matter physics in pure Python. No libraries — just the mathematics of quantum solids expressed as functions. Each lesson introduces one concept, explains the physics, and asks you to write the formula as code.
You will implement:
- Bragg diffraction — X-ray scattering from crystal planes and d-spacing from Miller indices
- Fermi energy — the highest occupied electron state in a free electron metal
- Fermi-Dirac distribution — the quantum statistics governing electrons at finite temperature
- Debye model — phonon heat capacity with the correct low-temperature T³ behavior
- Einstein model — heat capacity from independent quantum oscillators
- Phonon dispersion — the ω(k) relation for a 1D atomic chain
- Hall effect — carrier density from transverse voltage in a magnetic field
- Semiconductor carriers — intrinsic carrier concentration and the band gap
- Superconductivity — BCS energy gap, London penetration depth, and GL parameter
- Curie-Weiss law — magnetic susceptibility in paramagnets and ferromagnets
- Band gap and optical absorption — photon absorption edge and direct-gap coefficient
- Thermal conductivity — kinetic theory and the Wiedemann-Franz law
- Electronic heat capacity — the Sommerfeld γT contribution from conduction electrons
- Tight-binding model — band structure, effective mass, and group velocity in 1D
- Meissner effect — field expulsion, London equations, and critical fields