1. One-dimensional trap. In the one-dimensional trap of Fig. 39-2, fitting an electron
wave to the trap’s width L requires the single quantum number n.Therefore,
any electron confined to the trap must have a certain value of n, and its
quantum number ms can be either or . The two electrons could have
different values of n, or they could have the same value of n if one of them is
spin up and the other is spin down.