Spin video: the role of electron spin in a two-electron state. (symmetry, fermions and all that)

 Please post comments and questions here.


Andrew Hudson's question: "You said in the video that delta is proportional to the inverse of the Coulomb force, and it makes sense to have some sort of correction factor for the wave spilling over into the other well for the Psi plus state, but I'm still kind of unclear as to what delta is representing here."
What delta represents is, as you say, the ability of the electron wave to spill over into the other well. To get a perspective on delta, what it means and represents here, let's go back to the case where there is no coulomb force (between electrons). In that case delta is equal to 1. That will lead to the familiar $\frac{1}{\sqrt{2}}$ factor and a state that has equal weight in either well. Does that make sense?
             In the context of this video, we are in a very different regime, where coulomb repulsion is fairly strong and delta is about .3 to .001, roughly speaking. When delta is .3, then about 10% of the probability density is associated the secondary well, and about 90% with the primary well, so mostly the state has the electron in a particular well, but it allows some freedom to extend into the secondary well (for that state). What delta represents is the freedom for the electron to not be completely constrained to be only in one well. It is a relaxing of constraint toward the more general state, e.g., $\psi_{A'} = \frac{1}{\sqrt{1+\delta^2}}\psi_A + \frac{\delta}{\sqrt{1+\delta^2}}\psi_B$. Does that make sense?