Single-valued wavefunction
= Single-valued wavefunction
An ordinary scalar <wavefunction> assigns one complex amplitude to each physical configuration. In <polar coordinates> without an additional twisted boundary condition, the points $(r,\phi)$ and $(r,\phi+2\pi)$ are identical, so the angular factor must be periodic. An angular <eigenfunction> $e^{im\phi}$ therefore requires integer $m$. This scalar orbital condition does not rule out half-integer intrinsic <spin>.