Wave Packet Dynamics

a b
c

a) A displaced ground state of a simple harmonic oscillator of the correct width (i.e., a coherent state) oscillates back and forth with constant width.

b)   If the wave packet width or variance in a) is initially squeezed, it will spread for a quarter of a cycle, then return to the squeezed value at the half-cycle, spread for another quarter of a cycle, and so on.

c) Squeezed vacuum state:  the wave packet width or variance is oscillating in a simple harmonic oscillator potential well.  The packet initially had a squeezed variance.

The paths traced by the oscillating packets as a function of time are also available as animations.

Expanded/Modified from: P. Meystre and M. Sargent III, Elements of Quantum Optics, Springer-Verlag, 1991.

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