This is the last of five modules to introduce concepts and current frontiers of atomic physics and to prepare you for cutting-edge research:

- 8.421.1x: Resonance

- 8.421.2x: Atomic structure and atoms in external field

- 8.421.3x: Atom-Light Interactions 1 -- Matrix elements and quantized field

- 8.421.4x: Atom-Light interactions 2 -- Line broadening and two-photon transitions

- 8.421.5x: Coherence

This fifth module, 8.421.5x, looks at a central theme of atomic physics - coherence. This includes coherence of single atoms for two-level systems and three-level systems, and coherence between atoms, which can result in superradiant behavior.

At MIT, the content of the five modules makes the first of a two-semester sequence (8.421 and 8.422) for graduate students interested in Atomic, Molecular, and Optical Physics. This sequence is required for Ph.D. students doing research in this field.

In these modules you will learn about the interaction of radiation with atoms: resonance; absorption, stimulated and spontaneous emission; methods of resonance, dressed atom formalism, masers and lasers, cavity quantum electrodynamics; structure of simple atoms, behavior in very strong fields; fundamental tests: time reversal, parity violations, Bell's inequalities; and experimental methods.

Completing the two-course sequence allows you to pursue advanced study and research in cold atoms, as well as specialized topics in condensed matter physics.

The physics of atomic coherence, including:

- Three-level atomic systems

- Electromagnetically induced transparency

- Slow light

- Superradiance