A general spin state is a spinor: [ |\psi\rangle = a |+\rangle + b |-\rangle = \beginpmatrix a \ b \endpmatrix,\quad |a|^2 + |b|^2 = 1. ]
While widely recommended as a "short-cut" for test prep or self-study, some reviewers note that the book's emphasis on calculation sometimes comes at the expense of deep physical intuition. Additionally, like many texts in this series, it has been noted for having numerous typos in its mathematical formulas, which requires readers to stay alert during study. Quantum Mechanics Demystified 2nd Edition David McMahon
[ \hatL^2 |l,m\rangle = \hbar^2 l(l+1) |l,m\rangle, \quad l = 0, 1, 2, \dots ] [ \hatL_z |l,m\rangle = \hbar m |l,m\rangle, \quad m = -l, -l+1, \dots, l. ] A general spin state is a spinor: [
It does not replace the rigor of a university course, nor does it pretend to. Instead, it acts as a patient tutor. It acknowledges that quantum mechanics is hard , but it proves that it is not magic . [ \hatL^2 |l,m\rangle = \hbar^2 l(l+1) |l,m\rangle, \quad