Two electrons can occupy the same orbital given opposite values of this quantity.
In the XY model, above the Kosterlitz-Thouless transition temperature, the universal jump occurs when this type of stiffness goes to zero. Elements of the representations of the group of this name transform into their negative with a 360 degree rotation. Thomas precession adds a factor of 1/2 to the interaction energy between this quantity and orbital (*) angular momentum. In the Ising model, magnetization equals the magnetic moment times the sum over all sites of this quantity, which if aligned leads to ferromagnetism. Two electrons can occupy the same orbital given opposite values of this quantity. Bosons have integer values of this quantity while fermions have half integer values of quantity. For 10 points, give this quantum number.
In the XY model, above the Kosterlitz-Thouless transition temperature, the universal jump occurs when this type of stiffness goes to zero.
spin [accept spin angular momentum]