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Low Temperature Physics and Techniques

Class at Faculty of Mathematics and Physics |
NFPL168

Syllabus

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1. Introduction Notion of low temperature physics. History of reaching and use of low temperatures. Ways to absolute zero. Review of liquefying and cooling methods. *

2. Superfluidity Superfluid 4He. Experiments in He II. Bose-Einstein statistics. Two-fluid model. Landau theory of excitations. Feynman theory of vortices. Sound propagation in He II. Ions in liquid He. Superfluid 3He phases. Fermi-Dirac statistics. Condensates, dynamic and magnetic properties of the A, A1 and B phases. Nuclear magnetic resonance (NMR) experiments. Topology and collective modes. Rotating superfluid 3He. Mixture of 3He and 4He, dilution refrigerator. Pomeranchuk effect. Solid 4He and 3He. Magnetism of solid 3He. *

3. Superconductivity Electrical resistance, Meissner effect. London equation. Magnetic properties of superconductors. Microscopic theory, BCS theory. Flux quantization, quantum vortices. Weak superconductivity, Josephson effects, SQUID. High temperature superconductors. *

4. Magnetism at low temperature Paramagnetism, adiabatic demagnetization. Nuclear magnetism, nuclear demagnetization. Static orientation of nuclear moments. NMR and relaxation at low temperatures. Magnetic thermometry (susceptibility, nuclear orientation, NMR thermometry). *

5. Selected topics of solid state physics at low temperature Heat capacity of solids, thermal relaxation. Heat transfer, Kapitza resistance. Resistance thermometry. Quantum Hall effect.

Annotation

Basic properties of cryogenic liquids, Joule-Thomson effect, principles of helium liquefier. Mechanical and electrical properties of materials at low temperatures.

Bath and flow cryostats. Suoerconducting magnets. 3He - 4He mixtures, dilution refrigerator.

Adiabatic demagnetization of paramagnetic salts, nuclear demagnetization. Pomeranchuk effect.

Cooling methods based on transport effects in solids. Low temperature thermometry.

Kapitza resistance. Low temperature relaxation process.