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:
“Its quick silver bell beating, beating
And down the dark one ruby flare
Pulsing out red light like an artery,”
—Karl Shapiro (b. 1913)
“Love is a great thing. It is not by chance that in all times and practically among all cultured peoples love in the general sense and the love of a man for his wife are both called love. If love is often cruel or destructive, the reasons lie not in love itself, but in the inequality between people.”
—Anton Pavlovich Chekhov (18601904)
“The urgent consideration of the public safety may undoubtedly authorise the violation of every positive law. How far that or any other consideration may operate to dissolve the natural obligations of humanity and justice, is a doctrine of which I still desire to remain ignorant.”
—Edward Gibbon (17371794)