# Concepts in Magnetism and Superconductivity

- Institution: IIT Kharagpur
- Department: Physics
- Teacher: Prof. A Taraphder
- Level: Undergraduate
- Language: English
- Subjects: Physics
- Source: [NPTEL](https://nptel.ac.in/courses/115105131)
- Licence: [CC BY-NC-SA](https://nptel.ac.in/faq) (Non-commercial use only.)
- Syllabus: [at the source](https://nptel.ac.in/courses/115105131)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

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

1. [Lecture 01 : Introduction : Magnetism and superconductivity as macroscopic quantum phenomena](https://invisiblenetwork.ai/learn/nptel/115105131/8b0840832bef) (YouTube)
2. [Lecture 02 : Bohr magneton, BvL theorem](https://invisiblenetwork.ai/learn/nptel/115105131/b13448e5c23c) (YouTube)
3. [Lecture 03 : An electron in a magnetic field, magnetism of isolated atoms](https://invisiblenetwork.ai/learn/nptel/115105131/1dffeef16167) (YouTube)
4. [Lecture 04 : Magnetism of isolated atoms (Contd.), Diamagnetism](https://invisiblenetwork.ai/learn/nptel/115105131/a4d420a70368) (YouTube)
5. [Lecture 05 : Magnetism of atoms - dia and paramagnetic susceptibilities. Hund's rules, Van Vleck paramagnetism](https://invisiblenetwork.ai/learn/nptel/115105131/29b32fb2bd89) (YouTube)
6. [Lecture-6 : Van Vleck paramagnetism (Contd.), Paramagnetism](https://invisiblenetwork.ai/learn/nptel/115105131/f51a6386b641) (YouTube)
7. [Lecture-7 : Curie's law for arbitrary J, adiabatic demagnetization](https://invisiblenetwork.ai/learn/nptel/115105131/bc57188a31ea) (YouTube)
8. [Lecture-8 : Paramagnetism of conduction electrons - Pauli paramagnetism](https://invisiblenetwork.ai/learn/nptel/115105131/ce7df26e30d5) (YouTube)
9. [Lecture-9 : Ions in a solid: crystal field, orbital quenching, Jahn-Teller effect](https://invisiblenetwork.ai/learn/nptel/115105131/c221ca91b5be) (YouTube)
10. [Lecture-10 : Jahn-Teller effect (Contd.), Magnetic resonance techniques NMR, ESR](https://invisiblenetwork.ai/learn/nptel/115105131/80836e88c40d) (YouTube)
11. [Lecture-11 : Resonance techniques (Contd.), Recapitulation and overview](https://invisiblenetwork.ai/learn/nptel/115105131/f4de1e6ea5e3) (YouTube)
12. [Lecture-12 : Recapitulation, interacting moments and long range order, dipolar exchange, scales of energy and origin of exchange](https://invisiblenetwork.ai/learn/nptel/115105131/03d200101b65) (YouTube)
13. [Lecture-13 : Interacting moments, 2-electron system, origin of exchange and spin Hamiltonian](https://invisiblenetwork.ai/learn/nptel/115105131/41fadf4e14e3) (YouTube)
14. [Lecture-14 : Spin Hamiltonian, Heisenberg model, Exchange interactions: direct, super indirect itinerant exchange](https://invisiblenetwork.ai/learn/nptel/115105131/2b77b48446d8) (YouTube)
15. [Lecture-15 : GMR, spin model and mean-field theory, Ising model](https://invisiblenetwork.ai/learn/nptel/115105131/a835b28ea7fa) (YouTube)
16. [Lecture-16 : Ising model and its properties](https://invisiblenetwork.ai/learn/nptel/115105131/e8ead271034c) (YouTube)
17. [Lecture-17 : Ising model and its properties (Contd.), absence of LRO in d=1, mean-field theory](https://invisiblenetwork.ai/learn/nptel/115105131/5857002448ac) (YouTube)
18. [Lecture-18 : Ising model recap, applications, exact solutions](https://invisiblenetwork.ai/learn/nptel/115105131/95d218c0334c) (YouTube)
19. [Lecture-19 : Exact solution of Ising model in d=1, exact results in d=2. Mermin-Wagner theorem on the absence of LRO](https://invisiblenetwork.ai/learn/nptel/115105131/7b488028f38f) (YouTube)
20. [Lecture-20 : Recap - Exact solution of Ising model. Mermin-Wagner theorem on the absence of LRO, 2d xy model](https://invisiblenetwork.ai/learn/nptel/115105131/706ec0ec7f7d) (YouTube)
21. [Lecture-21 : Ferromagnetic Heisenberg model ground state](https://invisiblenetwork.ai/learn/nptel/115105131/6580bf44d89c) (YouTube)
22. [Lecture-22 : Ferromagnetic Heisenberg model, spin-waves and magnons](https://invisiblenetwork.ai/learn/nptel/115105131/f7aece2d9ad2) (YouTube)
23. [Lecture-23 : Antiferromagnetic Heisenberg model, AF magnetic structures](https://invisiblenetwork.ai/learn/nptel/115105131/8da7936e6312) (YouTube)
24. [Lecture-24 : AF magnetic structures, susceptibility and excitations](https://invisiblenetwork.ai/learn/nptel/115105131/afef9ffd0553) (YouTube)
25. [Lecture-25 : Antiferromagnets and frustration, spin glass](https://invisiblenetwork.ai/learn/nptel/115105131/d9cb49093935) (YouTube)
26. [Lecture-26 : Superconductivity: discovery, properties](https://invisiblenetwork.ai/learn/nptel/115105131/86fceb0e82b7) (YouTube)
27. [Lecture-27 : Superconductivity: Meissner effect, London Equation](https://invisiblenetwork.ai/learn/nptel/115105131/824d3b8f1597) (YouTube)
28. [Lecture-28 : Electron-phonon interaction, Cooper problem](https://invisiblenetwork.ai/learn/nptel/115105131/765f560f2cef) (YouTube)
29. [Lecture-29 : Cooper problem, setting up the BCS theory](https://invisiblenetwork.ai/learn/nptel/115105131/491a07cccd3f) (YouTube)
30. [Lecture-30 : BCS wave function, the Superconducting state and calculations of various properties](https://invisiblenetwork.ai/learn/nptel/115105131/7338b5ad0020) (YouTube)
31. [Lecture-31 : BCS theory (Contd.), energy gap, transition temperature](https://invisiblenetwork.ai/learn/nptel/115105131/a8782f4b0537) (YouTube)
32. [Lecture-32 : Consequences of BCS theory, gap vs T, Transition temperature, specific heat, tunnelling](https://invisiblenetwork.ai/learn/nptel/115105131/81fd4e66f206) (YouTube)
33. [Lecture-33 : Transition temperature, specific heat, tunnelling](https://invisiblenetwork.ai/learn/nptel/115105131/64f184e540f3) (YouTube)
34. [Lecture-34 : Andreev reflection, Ginzburg-Landau Theory and electrodynamics of superconductors](https://invisiblenetwork.ai/learn/nptel/115105131/71dd484f0a46) (YouTube)
35. [Lecture-35 : Ginzburg-Landau theory, coherence length and Type I and II superconductors](https://invisiblenetwork.ai/learn/nptel/115105131/201a7f3850a5) (YouTube)
36. [Lecture-36 : Flux lattice, Flux quantization, Josephson junctions](https://invisiblenetwork.ai/learn/nptel/115105131/5f65c616344b) (YouTube)
37. [Lecture-37 : Josephson effect and Josephson junctions](https://invisiblenetwork.ai/learn/nptel/115105131/371888bc9331) (YouTube)
38. [Lecture-38 : SQUID, Quantum computers and Josephson junction Qubits](https://invisiblenetwork.ai/learn/nptel/115105131/383bf4278920) (YouTube)
39. [Lecture-39 : High-Temperature Superconductivity: an enduring enigma](https://invisiblenetwork.ai/learn/nptel/115105131/788d574f8707) (YouTube)
40. [Lecture-40 : Overview and conclusion](https://invisiblenetwork.ai/learn/nptel/115105131/685b76bac9e4) (YouTube)