Demonstration of A Bell Inequality Violation
Now choose as the orientation angles of the transmission axes
-
a = 0, a′ = π/4, b = π/8, b′ = 3 π/8.
(6)
Then
-
EΦ(a, b) = cos 2(π/8) = 0.707,
(7a)
-
EΦ(a, b′) = cos 2(3π/8) = −0.707,
(7b)
-
EΦ(a′, b) = cos 2(−π/8) = 0.707,
(7c)
and
-
EΦ(a′, b′) = cos 2(π/8) = 0.707.
(7d)
Therefore the quantum mechanical prediction for the CHSH test statistic is
-
SΦ = EΦ(a, b) − EΦ(a, b′) + EΦ(a′, b) + EΦ(a′, b′) = 2.828,
(8)
exceeding the CHSH Bell test limit of 2 and thus completing the proof of a version of Bell's Theorem. In fact, all entangled quantum states yield predictions in violation of the inequality, as Gisin (1991) and Popescu and Rohrlich (1992) have independently demonstrated. Popescu and Rohrlich (1992) also show that the maximum amount of violation is achieved with a quantum state of maximum degree of entanglement, exemplified by |Φ> of Eq. (1).
Read more about this topic: Quantum Mechanical Bell Test Prediction
Famous quotes containing the words bell, inequality and/or violation:
“Those feelings of envy are familiar to many of us. We see our children accomplishing things that weve always been afraid to try, or we give them opportunities that we never had, and we find ourselves feeling jealousy mixed with our pride, or we feel resentful when they take it all for granted.”
—Ruth Davidson Bell (20th century)
“Nature is unfair? So much the better, inequality is the only bearable thing, the monotony of equality can only lead us to boredom.”
—Francis Picabia (18781953)
“Every violation of truth is not only a sort of suicide in the liar, but is a stab at the health of human society.”
—Ralph Waldo Emerson (18031882)