- #1
annaphys
- 69
- 1
In quantum mechanics one sees what J^2 can offer but why do we even consider looking at the eigenstates and eigenvalues of J^2 and a component of J, say J_z? Why don't we just use J?
why do we even consider looking at the eigenstates and eigenvalues of J^2 and a component of J, say J_z? Why don't we just use J?
##J^2## is easier to work with because it's defined as ##J^2 = J_x^2 + J_y^2 + J_z^2##. You could try to work with ##J = \sqrt{J^2}## as the magnitude of total AM, but I suspect it would be more awkward to work with.So the only reason we use J^2 is because it's a scalar?