A system design for evanescently trapping a 87Rb BEC using silicon nitride strip waveguides

Cold-atom systems have emerged as a highly promising avenue for quantum-enhanced position, navigation, and timing applications. However, their wider adoption is currently hampered in part by the large footprint of the systems. In leveraging the miniaturisation possible through photonic integrated circuits, cold-atom sensors would be able to reach much wider commercial adoption. In this paper, we a propose a system for evanescently trapping 87 Rb BECs using strip silicon nitride waveguides buried in silica using red- and blue-detuned fundamental and higher-order modes, providing a three-dimensional adjustable trap for BEC-based, chip-scale work in quantum science and technologies. Requiring no external lasers for PIC loading and capable of trapping bulk atom clouds, our method – when combined with other existing miniaturising technologies – can potentially produce shoebox or smaller sized deployable ultracold atom systems.