When does ΔxΔp equal h/4pi in the uncertainty principle?

[bs vasanth]

When it actually 'equal to' in uncertainty principle?
For example under what conditions:
ΔxΔt = h/4$pi$

 

[atyy]

The Gaussian is an example of a wave function in which the equality is satisfied.

A more general class are called "coherent states".
http://www.indiana.edu/~ssiweb/C561/PDFfiles/Uncertainty2008.pdf
http://www.fysik.su.se/~hansson/KFT2/extra notes/cstates copy.pdf

From the first of the above two links:
"In summary, we have seen that the coherent states are minimal uncertainty wavepackets which remains minimal under time evolution. Furthermore, the time dependent expectation values of x and p saties the classical equations of motion. From this point of view, the coherent states are very natural for studying the classical limit of quantum mechanics."

 

[marcusl]

Your statement of the uncertainty principle should read ΔxΔp.