Figure 7

CHSH parameter S as a function of θ when \(\delta = 0\), \(\delta ^{\prime} = \pi /4\) and \(\theta ^{\prime} = 3\pi /8\). Maximum violation of CHSH inequality is obtained when pairs θ, \(\theta ^{\prime}\) and δ, \(\delta ^{\prime}\) are orthogonal to each other. With decrease in entanglement visibility we see decrease in the maximum value of S and transition from violation of CHSH inequality to validation of CHSH inequality is seen around when visibility crosses 70%