Abstract:
We use the reduced density matrix of the two-particle spin state to construct
a generalized Bell–Clauser–Horne–Shimony–Holt inequality. For each
specific state and under a special choice of the vectors $\vec a$, $\vec b$, $\vec c$, and
$\vec d$, this inequality becomes an exact equality. We show how such
vectors can be found using the reduced density matrix. Both sides of this
equality have a specific numerical value. We indicate the connection of this
number with the measure of entanglement of the two-particle spin state.
Keywords:quantum mechanics, entangled state, density matrix, Bell inequality.