Scalable Multilayer Architecture of Assembled Single-Atom Qubit Arrays in a Three-Dimensional Talbot Tweezer Lattice

We report on the realization of a novel platform for the creation of large-scale 3D multilayer configurations of planar arrays of individual neutral-atom qubits: a microlens-generated Talbot tweezer lattice that extends 2D tweezer arrays to the third dimension at no additional costs. We demonstrate the trapping and imaging of rubidium atoms in integer and fractional Talbot planes and the assembly of defect-free atom arrays in different layers. The Talbot self-imaging effect for microlens arrays constitutes a structurally robust and wavelength-universal method for the realization of 3D atom arrays with beneficial scaling properties. With more than 750 qubit sites per 2D layer, these scaling properties imply that 10 000 qubit sites are already accessible in 3D in our current implementation. The trap topology and functionality are configurable in the micrometer regime. We use this to generate interleaved lattices with dynamic position control and parallelized sublattice addressing of spin states for immediate application in quantum science and technology.

Figure 1

Microlens-array generated Talbot tweezer lattice. (a) Schematic of the experimental setup. The MLA generates a 2D periodic spot pattern in its focal plane that is reproduced in Talbot planes. After reimaging and demagnification, these recurring self-images form a regular 3D multilayer lattice of 2D periodic optical microtrap arrays (for clarity, only three planes are drawn). (b) Detail of a 2D projection of the calculated intensity distribution (color coded) associated with a Talbot tweezer lattice created by an array of Gaussian beams. The principal planes $T_0,T_{\pm 1/2},T_{\pm 1},\dots$ are separated by $z_T/2$ and show a trap pitch identical to the one of the focal plane $T_0$. Parameters are according to the experiment: $\lambda =798.6\mathrm{nm}$, $a=14.1(4)\mathrm{\mu }\mathrm{m}$, $z_T/2=248(14)\mathrm{\mu }\mathrm{m}$, $w_0=1.45(10)\mathrm{\mu }\mathrm{m}$. (c) Averaged fluorescence images of single-atom arrays in integer and fractional Talbot planes (see text for details).

Figure 2

In-plane assembly of defect-free target structures of individual atoms using an auxiliary transport tweezer. The reimaged focal plane $T_0$ (a) and the Talbot plane $T_{-1/2}$ (b) are shown (atom arrays are centered in the images due to cropping). Parameters: $\lambda =797.3\mathrm{nm}$, $a=10.3(3)\mathrm{\mu }\mathrm{m}$, $z_T/2=133(8)\mathrm{\mu }\mathrm{m}$, $w_0=1.45(1)\mathrm{\mu }\mathrm{m}$, transport tweezer size (waist) $2.0(1)\mathrm{\mu }\mathrm{m}$. The in situ atomic fluorescence of individual atoms at resolved trapping positions reveals the initial atom distribution [left in (a),(b)] and the successful creation of a $9\times 9$ cluster via atom-by-atom assembly in both Talbot planes [right in (a),(b)]. The assembly process involves multiple cycles of atom rearrangement and position detection.

Figure 3

Scaling properties of the Talbot tweezer lattice and large-scale implementation. (a) The integral number of traps of all principal planes in the 3D lattice shows a scaling of $N_{\mathrm{int}}\propto P^{3/2}$ as function of the trap laser power. The scaling is plotted for the two experimental values of $w_0/a=0.10$ [red dashed, corresponding to Figs. 1 and 4] and $w_0/a=0.14$ [blue, corresponding to Figs. 2 and 3]. In one plane (2D array), the number of traps is directly proportional to the laser power (green, linear scaling). (b) Experimental implementation of a 3D tweezer lattice with ${10}^4$ traps [see indication in (a) and text for details]. The image shows a $19\times 19$ detail of single atoms stored in the plane $T_{-1/2}$ (averaged fluorescence). (c) Intensity and trap number variation along the Talbot tweezer lattice of Fig. 3. The intensity of the central trap normalized to $T_0$ is given for the ideal model (dashed blue line) and the model including uncertainties (blue dots). Green dots depict the in-plane number of traps (right axis).

Figure 4

Interleaved configurations of two Talbot tweezer lattices. All images show averaged fluorescence of the $T_{1/2}$ plane and the geometries are visualized by red and blue dots depicting the sites of the two lattices. (a) Single atom arrays with tunable atom separation. The separation of neighboring traps is (from left to right): $9.9(3)\mathrm{\mu }\mathrm{m}$, $7.0(2)\mathrm{\mu }\mathrm{m}$, and $5.0(2)\mathrm{\mu }\mathrm{m}$. (b) Sublattice-exclusive addressing (green, middle) is used to convert a spin-polarized array ($F=2$, left) to a configuration of columnwise antiferromagnetic ordering via preparation of alternating spin states ($F=2$ and $F=3$, right). State-selective detection records fluorescence for atoms in $F=2$.