Learn · NPTEL

Course11510513140 lectures

Concepts in Magnetism and Superconductivity

Prof. A Taraphder · IIT Kharagpur

Start with lecture 1 At NPTEL

About

The course aims to introduce and work through the underlying concepts behind magnetism and superconductivity. Starting from an electron in a magnetic field, the magnetic responses of a collection of atoms in a solid are worked out. Magnetization and susceptibility in para and diamagnetic cases, their applications and excitations are discussed. Superconductivity: zero resistance, Meissner effect, perfect diamagnetism; BCS theory, energy gap, isotope effect and tunneling experiments worked out. Josephson junctions and their applications, qubits and quantum chips discussed. Novel high-TC superconductor introduced. The emphasis is on working things out from very simple physical concepts.

Intended audience: B Tech, BE, M Tech, ME, MSc, PhD

Prerequisites: Modern physics and elementary quantum mechanics, basic ideas in condensed matter or solid-state physics

Lectures

Week 1

  1. Lecture 01 : Introduction : Magnetism and superconductivity as macroscopic quantum phenomena YouTube
  2. Lecture 02 : Bohr magneton, BvL theorem YouTube
  3. Lecture 03 : An electron in a magnetic field, magnetism of isolated atoms YouTube
  4. Lecture 04 : Magnetism of isolated atoms (Contd.), Diamagnetism YouTube
  5. Lecture 05 : Magnetism of atoms - dia and paramagnetic susceptibilities. Hund's rules, Van Vleck paramagnetism YouTube

Week 2

  1. Lecture-6 : Van Vleck paramagnetism (Contd.), Paramagnetism YouTube
  2. Lecture-7 : Curie's law for arbitrary J, adiabatic demagnetization YouTube
  3. Lecture-8 : Paramagnetism of conduction electrons - Pauli paramagnetism YouTube
  4. Lecture-9 : Ions in a solid: crystal field, orbital quenching, Jahn-Teller effect YouTube
  5. Lecture-10 : Jahn-Teller effect (Contd.), Magnetic resonance techniques NMR, ESR YouTube

Week 3

  1. Lecture-11 : Resonance techniques (Contd.), Recapitulation and overview YouTube
  2. Lecture-12 : Recapitulation, interacting moments and long range order, dipolar exchange, scales of energy and origin of exchange YouTube
  3. Lecture-13 : Interacting moments, 2-electron system, origin of exchange and spin Hamiltonian YouTube
  4. Lecture-14 : Spin Hamiltonian, Heisenberg model, Exchange interactions: direct, super indirect itinerant exchange YouTube
  5. Lecture-15 : GMR, spin model and mean-field theory, Ising model YouTube

Week 4

  1. Lecture-16 : Ising model and its properties YouTube
  2. Lecture-17 : Ising model and its properties (Contd.), absence of LRO in d=1, mean-field theory YouTube
  3. Lecture-18 : Ising model recap, applications, exact solutions YouTube
  4. Lecture-19 : Exact solution of Ising model in d=1, exact results in d=2. Mermin-Wagner theorem on the absence of LRO YouTube
  5. Lecture-20 : Recap - Exact solution of Ising model. Mermin-Wagner theorem on the absence of LRO, 2d xy model YouTube

Week 5

  1. Lecture-21 : Ferromagnetic Heisenberg model ground state YouTube
  2. Lecture-22 : Ferromagnetic Heisenberg model, spin-waves and magnons YouTube
  3. Lecture-23 : Antiferromagnetic Heisenberg model, AF magnetic structures YouTube
  4. Lecture-24 : AF magnetic structures, susceptibility and excitations YouTube
  5. Lecture-25 : Antiferromagnets and frustration, spin glass YouTube

Week 6

  1. Lecture-26 : Superconductivity: discovery, properties YouTube
  2. Lecture-27 : Superconductivity: Meissner effect, London Equation YouTube
  3. Lecture-28 : Electron-phonon interaction, Cooper problem YouTube
  4. Lecture-29 : Cooper problem, setting up the BCS theory YouTube
  5. Lecture-30 : BCS wave function, the Superconducting state and calculations of various properties YouTube

Week 7

  1. Lecture-31 : BCS theory (Contd.), energy gap, transition temperature YouTube
  2. Lecture-32 : Consequences of BCS theory, gap vs T, Transition temperature, specific heat, tunnelling YouTube
  3. Lecture-33 : Transition temperature, specific heat, tunnelling YouTube
  4. Lecture-34 : Andreev reflection, Ginzburg-Landau Theory and electrodynamics of superconductors YouTube
  5. Lecture-35 : Ginzburg-Landau theory, coherence length and Type I and II superconductors YouTube

Week 8

  1. Lecture-36 : Flux lattice, Flux quantization, Josephson junctions YouTube
  2. Lecture-37 : Josephson effect and Josephson junctions YouTube
  3. Lecture-38 : SQUID, Quantum computers and Josephson junction Qubits YouTube
  4. Lecture-39 : High-Temperature Superconductivity: an enduring enigma YouTube
  5. Lecture-40 : Overview and conclusion YouTube

Syllabus and materials

At NPTEL, as the course publishes them.

Credits and licence

Institution
IIT Kharagpur
Department
Physics
Teacher
Prof. A Taraphder
Level
Undergraduate
Language
English
Subjects
Physics
Source
NPTEL
Licence
CC BY-NC-SA, as NPTEL states it. Non-commercial use only. NPTEL's terms
Attribution
NPTEL states: "Distributed under Creative Commons Attribution-ShareAlike / CC BY - NC - SA", beside a BY-NC-SA badge.
Who can watch
NPTEL gives no rating. Invisible Network shows it to Tweens profiles and older, judged from what the source says about it. How courses are placed