Double-slit atom interferometry as a demonstration of quantum mechanical measurements

Monika A. M. Marte, P. Zoller, Murray Holland +2 more

Ali Ayatollah Rafsanjani, MohammadJavad Kazemi, Alireza Bahrampour +1 more

Abstract Despite the astonishing successes of quantum mechanics, due to some fundamental problems such as the measurement problem and quantum arrival time problem, the predictions of the theory are in some cases not quite clear and unique. Especially, there are various predictions for the joint spatiotemporal distribution of particle detection events on a screen, which are derived from different formulations and interpretations of the quantum theory. Although the differences are typically small, we show that these predictions can be experimentally distinguished by a proposed unconventional double-slit configuration, which is realizable using present-day single-atom interferometry. This experiment would enrich our understanding of the foundations of quantum mechanics.

Daniel F. Walls, Sze Tan, Pippa Storey +1 more

Roger Bach

Quantum mechanics has fundamentally changed the way scientists think about the world. Quantum mechanical theory has found it's way into our everyday lives through advances in technology. In this dissertation a fundamental quantum mechanical demonstration and the technological development of a new quantum mechanical device are presented. Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. Here we demonstrate the full realization of Richard Feynman's famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individuals slits. Probability distributions for single- and double-slit arrangements were observed. Additionally, by recording single electron detection events diffracting through a double-slit,a diffraction pattern was built up from individual events. Additionally, a demonstration of a three grating Talbot-Lau interferometer for electrons is presented. As a proof of principle the interferometer is used to measure magnetic fields. The possibility to extend this work to build a scaled-up electron interferometer for sensitive magnetic field sensing is discussed. A theoretical model is presented to simulate the two experiments. This model is developed from Richard Feynman's path integral formalism, where a wave function is propagated through the elements of the system. The theoretical simulations reproduce the experimental data well, except for a large discrepancy of a factor of 5.5 between the experimental and theoretical sensitivity of the Talbot-Lau interferometer. The origin of the discrepancy is currently unknown. These experiments were built off of previous work done here at the University of Nebraska-Lincoln, and improvements to the preexisting system are discussed. While these experiments likely did not demonstrate anything contrary to conventional quantum mechanics, it is important to continually probe these types of experiments to test the fundamental principles of quantum mechanics and explore it's technical applications. Advisor: Herman Batelaan

Herman C. W. Beijerinck, K. A. H. van Leeuwen

Tycho Sleator, O. Carnal, Tilman Pfau +3 more

We present results on an interferometer for atoms based on Young's double-slit experiment. We also discuss proposed experiments in which the effect of spontaneous emission on the visibility of the atomic fringe pattern, as well as the effect of coherent atom-light interactions on the phase of the atomic wavefunction could be measured.