Observing Quantum Entanglement: Interference Patterns and Breaking Bell's Inequality
Katherine Frazer, Jayne Gazzola, Maeve Beckett, Maggie Oxford, Kyle Edmond · 2021
In this two-part experiment, we studied the interference pattern of a laser pointer interfering with itself through a Mach-Zehnder interferometer as well as tested Bell’s Inequality for entangled particles via parametric down conversion. The predicted results were a fringe pattern that was purely circular with distinct fringes, however, the results of the laser pointer interference were inconclusive due to significant error in the alignment of the interferometer. In reference to the second part of our lab, due to COVID-19 restrictions, time ran out for us to complete data collection of the coincidence counts between the down converted beams of our Gallium Nitride laser. We attributed the lack of coincidence counts to error in the precision of the alignment of the optical apparatus. Thus, we used reference data instead to calculate the statistic, S=2.31 ± 0.04, to compare with Bell’s Inequality of |S| ≤ 2. Our result using the reference data did exceed Bell’s Inequality, as was expected of quantum mechanics, being non-local.