Violating the LG inequality with K+.
Red dots represent the experimental results. Solid lines are the theoretical fittings employing equation (4). The dashed line represents the classical limit, −1. The x axis represents the total thickness of quartz plates between t1 and t2. The inset represents the oscillation between the maximum and minimum in the blue dashed pane (the x axis represents the total thickness of quartz plates between t1 and t2 and the y axis represents K+). Error bars correspond to the random fluctuation of each measured coincidence count and the tilt uncertainties of quartz plates.