M2intro.txt

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Welcome to the second module of the course
on atomic and optical physics.
In module one we focused on the theme of resonance and two
paradigmatic examples.
One was the harmonic oscillator and the other one
was a magnetic moment precessing in a magnetic field, which
is a realization of a two-level system.
Now we are addressing the question,
where do those levels come from?
Well, these are atomic states, discrete states
of a system consisting of an atomic nucleus and electrons.
In atomic physics the main actors are the atoms,
and in this module we are inviting them to come
to the stage of this course.
The ingredients of an atom go beyond just
positive and negative charges, because both the electron
and the nucleus have spin, and this gives rise
to additional richness called fine structure
and hyperfine structure.
Furthermore, the atomic states and the atomic energy levels
can be modified, and therefore controlled, by external fields,
by electric fields and magnetic fields.
This control of quantum states is
indispensable in the areas of quantum engineering
of new systems or quantum simulations.
And in this module, in module two of this course, you will learn about the concepts behind those tools.