QM Lecture 3

CHAPTER 3 The ORIGINS of QUANTUM PHYSICS

3.1 Blackbody radiation

3.1.A The Kirchoff’ Law and the concept of blackbody radiator

3.1.B Radiation in a cavity

Appendix:Analyzing electronic excitations with a mechanical forced harmonic oscillator model

3.1.C Radiation and thermal equilibrium

3.1.D The birthday of Quantum Physics: Planck’s Hypothesis

3.2 Particle-light properties of radiation

3.2.A Processes involving the absorption or scattering of radiation by particles

3.2.B Processes where interacting charged particles produce radiation

3.3 Wave-light properties of particles

3.3.A The de Broglie Hypothesis

3.3.B Experimental confirmation of the de Broglie hypothesis. Electron Diffraction

3.4 Wave-particle duality

Role of the smallness of Planck’s constant. Statistical interpretation

3.5 Einstein's Postulate of Quantized Radiation

3.5A Calculation of the Electromagnetic Energy Density U inside a cavity at temperature T

Concept of electromagnetic modes, counting modes present in a cavity, average energy

stored in a mode

3.5B Relationship between U (energy density) and I (light spectral density)

3.6 Light-matter Interaction: Einstein's Law of Radiation

3.6A Einstein's calculation of the average energy of an electromagnetic mode

Extension of Planck's quantization energy of matter to light energy quantization

3.6B Einstein's extension of light energy quantization to light-matter interaction

Einstein's coefficients: absorption of light, spontaneous and stimulate emission of light

3.6C Sustained Stimulated Emission: LASER

Optical pumping, laser resonator, absorption coefficient and population inversion

References

Richard Feynman, “The Feynman Lectures on Physics,” Volume I, Chapter 32 (Sections 32-1 to 32-3) and Chapeter 41 (Sections 41-2 and 41-3)

R. Eisberg and R. Resnick, “Quantum Physics,” 2nd Ed., Wiley, 1985. Chapters 1 and 3.