Trapping single atoms on a nanophotonic circuit with configurable tweezer lattices

Abstract

Trapped atoms near nanophotonics form an exciting platform for bottom-up synthesis of strongly interacting quantum matter. The ability to induce tunable long-range atom-atom interactions with photons presents an opportunity to explore many-body physics and quantum optics. Here we implement a configurable optical tweezer array over a planar photonic circuit tailored for cold atom integration and control for trapping and high-fidelity imaging of one or more atoms in an array directly on a photonic structure. Using an optical conveyor belt formed by a moving optical lattice within a tweezer potential, we show that single atoms can be transported from a reservoir into close proximity of a photonic interface, potentially allowing for the synthesis of a defect-free atom-nanophotonic hybrid lattice. Our experimental platform can be integrated with generic planar photonic waveguides and resonators, promising a pathway towards on-chip many-body quantum optics and applications in quantum technology.

Strong Coupling of Two Individually Controlled Atoms via a Nanophotonic Cavity

“…In particular, cold neutral atoms have recently emerged as a promising approach for realizing large-scale quantum systems due to the ability to generate large numbers of identical, individually trapped atoms [17][18][19][20][21]. While significant effort is currently being directed towards coupling multiple isolated atoms to nanophotonic systems [7,[22][23][24], achieving a strong coupling of a deterministic number of atoms remains a challenge. The atoms must be trapped closely enough to the device to maximize the coupling within the evanescent field, while overcoming attractive surface forces [25,26], and preserving the excellent atomic coherence properties.…”

“…The number of atoms can be scaled up by generating tweezer arrays [17][18][19][20][21]. The established techniques for assembling atom arrays can be combined with our approach for the individual addressing and light shift control and recently developed techniques for imaging an array on a nanophotonic structure [23]. Combining these capabilities with the ability to engineer band dispersion may allow for the exploration of novel many-body systems with extensive tunability.…”

Large array of Schrödinger cat states facilitated by an optical waveguide

“…Strong atom–light interactions can be achieved by trapping atoms in the cladding modes, which can be patterned by engineering the geometry and thickness of the cladding structure 40 . As silica fibreglass is transparent to light in the visible to near-infrared range, light propagating from the side into the fibre can also be used for controlling the internal and external degrees of freedom of atoms 41 . Other photonic crystal structures also possess similar degrees of freedom to control atoms at the single quantum state level.…”

Reduced volume and reflection for bright optical tweezers with radial Laguerre–Gauss beams

“…However, there are important settings for both particle trapping and imaging in which the focal region is not homogeneous but instead, contains significant spatial variations of the dielectric constant over a wide range of length scales from nanometers to micrometers. Important examples in atomic, molecular, and optical (AMO) physics include recent efforts to trap atoms near nanophotonic structures such as dielectric optical cavities and photonic crystal waveguides (PCWs) ( 26 , 39 , 43 – 46 ). These efforts have been hampered by large modification of the trapping potential of an optical tweezer in the vicinity of a nanophotonic structure, principally associated with specular reflection that produces high-contrast interference fringes extending well beyond the volume of the tweezer.…”