Atomic Moclecular and Laser Physics 2010

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Atomic, Molecular and Laser Physics

Instructor: Dr. [Sabieh Anwar] Office hours: Tuesday, Thursday (5-6 pm)

Teaching Assistant: [Shahid Sattar] Office hours: Tuesday, Thursday (4-6 pm)

Textbook: Molecular Quantum Mechanics, Fourth edition by Peter Atkins, Ronald Friedman


Course outline: Click here


Week 1 Spins in magnetic fields

  • Zeeman and singlet-triplet bases and their inter-conversion
  • Spin in an external magnetic field, magnetogyric ratio
  • Zeeman Hamiltonian
  • Bloch sphere and evolution of states on the sphere

Week 2 Spins in magnetic fields (continued)

  • Rotation operators, viewing a propagator as a rotation operator
  • evolution of observables
  • rotating wave approximation
  • NMR and ESR spectra

Week 3 Transitions between energy levels

  • Time-dependent perturbation theory basics: constant, exponentially increasing and oscillatory Hamiltonians
  • Approximate and exact formulas
  • Rabi flopping
  • rotating wave approximation revisited
  • Comparison between constant and oscillatory Hamiltonians

Week 4 Interaction of electric dipoles with Radiation

Spontaneously modulated spin textures in a dipolar spinor Bose-Einstein condensate (photograph by UC Berkley)
Spontaneously modulated spin textures in a dipolar spinor Bose-Einstein condensate (photograph by UC Berkley)
A laser-microscalpel which makes possible to target one cancer cell at a time. The inset demonstrates where the laser severs the axon(photograph by H. Cinar and Y. Jin)
A laser-microscalpel which makes possible to target one cancer cell at a time. The inset demonstrates where the laser severs the axon(photograph by H. Cinar and Y. Jin)
  • Transitions to continuum states
  • Fermi golden rule
  • Electric dipole interacting with an electromagnetic wave
  • Absorption, stimulated and spontaneous emission
  • Interaction with thermal radiation
  • Einstein's A and B coefficients

Week 5 Lifetimes of states

  • Natural broadening
  • Pressure broadening
  • Doppler broadening
  • Lorentzian and Gaussian lineshapes, lineshape function, homogeneous and heterogeneous broadening
  • What about lineshapes in solids?
  • Emission rates for a quantum harmonic oscillator and comparison with a classic accelerating electric dipole

Week 6 Selection rules

  • Selection rules for the magnetic quantum number

Week 7 Selection rules (contd.)

  • Selection rules for the orbital quantum number
  • Laporte rule: electric dipole transitions are allowed between opposite parity states
  • Examples of applications of selection rules
  • Grotrian diagram
  • Metastable states and phosphorescence
  • Angular momentum and helicity of the photon: Review article for self-study: A justification of selection rules Spectroscopic selection rules: The role of photon states (J. Chem. Ed., Vol. 76 No. 9, 1999)

Week 7 and 8 Atomic Spectrum of hydrogen: fine structure



This image shows the mapping of Milky way at different wavelengths.
This image shows the mapping of Milky way at different wavelengths.

Week 9 Zeeman and hyperfine effects

  • The Zeeman effect: weak and strong fields
  • Effect on the spectrum by placing the atom in external magnetic field
  • Hyperfine interaction
  • The 21 cm line and some of its uses in radio-astronomy
  • The F quantum number

Week 10 Multi-electron atoms (before the spin-orbit interaction)

  • Pauli's exclusion principle, fermions and bosons
  • Why does the singlet electron state has a higher energy than the triplet electron state?
  • Effect of Coulombic repulsion on He levels: ground and first excited state
  • Hartree's theory and its important results
  • Concept of effective nuclear charge
Bose-Einstein condensation at 400, 200 and 50 nK. A very dense blob formed at the center is representing the condensate.
Bose-Einstein condensation at 400, 200 and 50 nK. A very dense blob formed at the center is representing the condensate.

Week 11 The Periodic Table

  • The Periodic Table and ground state electronic configurations
  • Electronic configurations and anomalies
  • Why does energy depend on l?
  • Trends in the periodic table explicable from Hartree's calculations
  • Guest lecture by Rafiullah: Bose-Einstein condensation

Review article for self-study: Bose-Einstein condensation (Source: Physicsworld.com)
Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor (Science, Vol 269, 1995)


Week 12 Spectroscopy of Multi-electron Atoms

  • Electronic configurations, terms, levels and states
  • Hund's rules
  • Examples of atomic spectra: helium, alkali metals (lithium, sodium etc), alkaline earth (calcium etc)
  • Atomic absorption spectroscopy
  • X-ray spectroscopy
  • Photoelectron spectroscopy: X-ray Fluorescence and Auger electron spectroscopy
  • Zeeman effect in multi-electron systems

Week 13 Lasers

  • Review of spontaneous emission, stimulated emission and absorption
  • Population inversion and conditions for laser operation
  • Gain of the laser medium, laser as an amplifier
  • laser as an oscillator
  • Single and multi mode operation
  • Pulsed mode operation: Q-switching and mode-locking
  • Characteristics of laser light
  • Some example lasers: He-Ne, excimer, Nd:YAG and diode lasers


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