Virtual probability current associated with the spin

摘要

A simple derivation of the spin probability current density from the expectation value of the spin operator is given. The properties of the spin probability current density are then examined in detail. We show that the spin probability current is solenoidal, virtual, and gives null contribution to the momentum of the particle. Expressions of the spin probability current density are derived for the Gaussian wave packet and the s states of the hydrogen atom. (C) 2000 American Association of Physics Teachers. [References: 13]