Spin (physics) Spin (physics) In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei. Spin is one of two types of angular momentum in quantum mechanics, the other being "orbital angular momentum". The orbital angular momentum operator is the quantum-mechanical counterpart to the classical angular momentum of orbital revolution and appears when there is periodic structure to its wavefunction as the angle varies. The existence of spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible
Institute for Theoretical Atomic, Molecular and Optical Physics Institute for Theoretical Atomic, Molecular and Optical Physics The Institute for Theoretical Atomic, Molecular and Optical Physics (ITAMP) is an international scientific learned society based at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. It was established in 1988 to alleviate a perceived shortage of theorists in atomic, molecular, and optical physics (AMO) at major universities throughout America. AMO concerns the study of matter-matter and light-matter interactions at the scale of one or a few atoms. The stated objectives of the Institute are: The objectives are tackled by fostering an intellectually stimulating environment, developing pioneering research areas, facilitating closer interactions