**PH-605 Condensed Matter Theory-I**

- Introduction: Overview of modern condensed matter physics, more is different, emergent properties.
- Broken symmetry, quasiparticles and collective phenomena: Symmetry, importance of broken symmetry, adiabatic continuity and universality.
- Landau’s Fermi liquid theory: The free electron theory, why does the free electron theory work so well? Adiabatic continuity applied to Fermi systems, Landau’s Fermi liquid theory, physical consequences.
- Second quantization and its applications: Bosons, Fermions, Fermion operators, quantum magnetism, spin waves and magnons, Su-Shriefer-Heeger model of a conducting polymer chain.
- Electron interactions: Hartree and Hartree-Fock theory, Metals in the Hartree-Fock approximation, correlation energy of jellium, Wigner crystallization, Inhomogeneous electron systems, Kohn-Hohenberg theory, The Kohn-Sham equation, Exchange-correlation functional.
- Response functions: An overview of modern experimental techniques, linear response theory, fluctuation-dissipation theorem, dielectric response function.
- Luttinger liquid theory: Why is 1D special? The Luttinger model, spin-charge separation.
- Electron-lattice interactions: harmonic chain, electron-phonon interaction, electrical conduction, effective electron-electron coupling.

**Recommended texts: **

*Advanced Solid State Physics*, by P. Philips, publisher: Westview Press; 1st edition, (2003).*Condensed Matter Field Theory*, by A. Altland and B. Simons, publisher: Cambridge University Press, 1st edition (2006).*Advanced Condensed Matter Physics*, by L. M. Sander, publisher: Cambridge University Press, 1st edition (2009).