Along with orbitons and holons, quasiparticles carrying this property are formed from electrons in Luttinger liquids, which carry density waves in charge and this property. Similar wave-like disturbances in the collective structure of this property for a crystal lattice are quantized into magnons. This property separates orthohydrogen from parahydrogen, and its total value is 0 for singlet states and 1 for triplet states. This property causes a beam of silver atoms sent through an inhomogeneous magnetic field to split into two beams instead of forming a continuous band. This property, described by a set of Hermitian unitary matrices named for Wolfgang Pauli, was discovered in the Stern-Gerlach experiment. For 10 points, name this intrinsic 
Along with orbitons and holons, quasiparticles carrying this property are formed from electrons in Luttinger liquids, which carry density waves in charge and this property. Similar wave-like disturbances in the collective structure of this property for a crystal lattice are quantized into magnons. This property separates orthohydrogen from parahydrogen, and its total value is 0 for singlet states and 1 for triplet states. This property causes a beam of silver atoms sent through an inhomogeneous magnetic field to split into two beams instead of forming a continuous band. This property, described by a set of Hermitian unitary matrices named for Wolfgang Pauli, was discovered in the Stern-Gerlach experiment. For 10 points, name this intrinsic form of angular momentum, whose quantum number can be plus or minus one-half for electrons.