quantum-mechanical operator

quantum-mechanical operator

[′kwän·təm mi′kan·ə·kəl ‚äp·ə‚rād·ər] (quantum mechanics) A linear, Hermitian operator associated with some physical quantity; for a physical system in any state, the expectation value of the physical quantity equals the integral over configuration space of ψ*(A ψ), where A ψ is the result of the operator acting on the wave function of the system, and ψ* is the complex conjugate of the wave function.