Learn · Concepts in Magnetism and Superconductivity
Lecture 19 of 40Week 4
Lecture-19 : Exact solution of Ising model in d=1, exact results in d=2. Mermin-Wagner theorem on the absence of LRO
Prof. A Taraphder · IIT Kharagpur
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All the lectures
- Lecture 01 : Introduction : Magnetism and superconductivity as macroscopic quantum phenomena
- Lecture 02 : Bohr magneton, BvL theorem
- Lecture 03 : An electron in a magnetic field, magnetism of isolated atoms
- Lecture 04 : Magnetism of isolated atoms (Contd.), Diamagnetism
- Lecture 05 : Magnetism of atoms - dia and paramagnetic susceptibilities. Hund's rules, Van Vleck paramagnetism
- Lecture-6 : Van Vleck paramagnetism (Contd.), Paramagnetism
- Lecture-7 : Curie's law for arbitrary J, adiabatic demagnetization
- Lecture-8 : Paramagnetism of conduction electrons - Pauli paramagnetism
- Lecture-9 : Ions in a solid: crystal field, orbital quenching, Jahn-Teller effect
- Lecture-10 : Jahn-Teller effect (Contd.), Magnetic resonance techniques NMR, ESR
- Lecture-11 : Resonance techniques (Contd.), Recapitulation and overview
- Lecture-12 : Recapitulation, interacting moments and long range order, dipolar exchange, scales of energy and origin of exchange
- Lecture-13 : Interacting moments, 2-electron system, origin of exchange and spin Hamiltonian
- Lecture-14 : Spin Hamiltonian, Heisenberg model, Exchange interactions: direct, super indirect itinerant exchange
- Lecture-15 : GMR, spin model and mean-field theory, Ising model
- Lecture-16 : Ising model and its properties
- Lecture-17 : Ising model and its properties (Contd.), absence of LRO in d=1, mean-field theory
- Lecture-18 : Ising model recap, applications, exact solutions
- Lecture-19 : Exact solution of Ising model in d=1, exact results in d=2. Mermin-Wagner theorem on the absence of LRO
- Lecture-20 : Recap - Exact solution of Ising model. Mermin-Wagner theorem on the absence of LRO, 2d xy model
- Lecture-21 : Ferromagnetic Heisenberg model ground state
- Lecture-22 : Ferromagnetic Heisenberg model, spin-waves and magnons
- Lecture-23 : Antiferromagnetic Heisenberg model, AF magnetic structures
- Lecture-24 : AF magnetic structures, susceptibility and excitations
- Lecture-25 : Antiferromagnets and frustration, spin glass
- Lecture-26 : Superconductivity: discovery, properties
- Lecture-27 : Superconductivity: Meissner effect, London Equation
- Lecture-28 : Electron-phonon interaction, Cooper problem
- Lecture-29 : Cooper problem, setting up the BCS theory
- Lecture-30 : BCS wave function, the Superconducting state and calculations of various properties
- Lecture-31 : BCS theory (Contd.), energy gap, transition temperature
- Lecture-32 : Consequences of BCS theory, gap vs T, Transition temperature, specific heat, tunnelling
- Lecture-33 : Transition temperature, specific heat, tunnelling
- Lecture-34 : Andreev reflection, Ginzburg-Landau Theory and electrodynamics of superconductors
- Lecture-35 : Ginzburg-Landau theory, coherence length and Type I and II superconductors
- Lecture-36 : Flux lattice, Flux quantization, Josephson junctions
- Lecture-37 : Josephson effect and Josephson junctions
- Lecture-38 : SQUID, Quantum computers and Josephson junction Qubits
- Lecture-39 : High-Temperature Superconductivity: an enduring enigma
- Lecture-40 : Overview and conclusion