The research presented in this dissertation aims to contribute to the field of atom optics via the implementation and demonstration of an all-optical one-way barrier for ⁸⁷Rb atoms—a novel tool for controlling atomic motion. This barrier—a type of atomic turnstile—transmits atoms traveling in one direction but hinders their passage in the other direction. We create the barrier with two laser beams, generating its unidirectional behavior by exploiting the two hyperfine ground states of ⁸⁷Rb. In particular, we judiciously choose the frequency of one beam to present a potential well to atoms in one ground state (the transmitting state) and a potential barrier to atoms in the other state (the reflecting state). The second beam optically pumps the atoms from the transmitting state to the reflecting state.

A significant component of the experimental work presented here involves generating ultra-cold rubidium atoms for demonstrating the one-way barrier. To this end, we have designed and constructed a sophisticated ⁸⁷Rb cooling and trapping apparatus. This apparatus comprises an extensive ultra-high vacuum system, four home-built, frequency-stabilized diode laser systems, a high-power Yb:fiber laser, a multitude of supporting optics, and substantial timing and control electronics. This system allows us to cool and trap rubidium atoms at a temperature of about 30 μK.

The results presented in this dissertation are summarized as follows. We successfully implemented a one-way barrier for neutral atoms and demonstrated its asymmetric nature. We used this new tool to compress the phase-space volume of an atomic sample and examined its significance as a physical realization of Maxwell's demon. We also demonstrated the robustness of the barrier's functionality to variations in several important experimental parameters. Lastly, we demonstrated the barrier's ability to cool an atomic sample, substantiating its potential application as a new cooling tool.

This dissertation includes previously published coauthored material.