M5L25d.txt

#
# File:   content-mit-8-421-5x-subtitles/M5L25d.txt
#
# Captions for 8.421x module
#
# This file has 28 caption lines.
#
# Do not add or delete any lines.
#
#----------------------------------------

So the question is, have those effects been observed?
Yes, they have actually, and they're
important for a lot of research.
But just for two atoms, the simplest observation
is when you take two atoms, let's say two sodium atoms,
bring them very close, and you form a sodium 2 molecule.
And to some extent, when the molecule are binding,
it's not-- for states where the molecule are binding,
it's not completely changing the electronic structure.
We can regard the sodium 2 molecule
as consisting of 2 sodium atoms.
And indeed, if you do spectroscopy of the sodium 2
molecule, you find some molecular state
which are very long lived, like the subradiance states which
do not radiate at all.
But then you find states which have a spontaneous emission
rate, which is about two times faster
than the atomic spontaneous emission rate.
So you find sort of that you can understand
some radiative properties of molecules
by assuming that they are related to the sub
and superradiance state of the two atoms
which formed this molecule.
So an example here is our-- is sodium
2 molecule has states with [INAUDIBLE] gamma molecule
is approximately 2 times gamma sodium,
or other states where it's very small.