We demonstrate deterministic preparation of arbitrary two-component product states of fermionic $^6$Li atoms in an 8$\times$8 optical tweezer array, achieving motional ground-state fidelities above $98.5\,\%$. Leveraging the large differential magnetic moments for spin-resolution, with parallelized site- and number-resolved control, our approach addresses key challenges for low-entropy quantum state engineering. Combined with high-fidelity spin-, site-, and density-resolved readout within a single $20\,\mathrm{μs}$ exposure, and $3\,\mathrm{s}$ experimental cycles, these advances establish a fast, scalable, and programmable architecture for fermionic quantum simulation.
We demonstrate deterministic preparation of arbitrary two-component product states of fermionic 6Li atoms in an 8×8 optical tweezer array, achieving motional ground-state fidelities above 98.5%. Leveraging the large differential magnetic moments for spin-resolution, with parallelized site- and number-resolved control, our approach addresses key challenges for low-entropy quantum state engineering. Combined with high-fidelity spin-, site-, and density-resolved readout within a single 20μs exposure, and 3s experimental cycles, these advances establish a fast, scalable, and programmable architecture for fermionic quantum simulation.
We prepare high-filling two-component arrays of tens of fermionic ^{6}Li atoms in optical tweezers, with the atoms in the ground motional state of each tweezer. Using a stroboscopic technique, we configure the arrays in various two-dimensional geometries with negligible Floquet heating. A full spin- and density-resolved readout of individual sites allows us to postselect near-zero entropy initial states for fermionic quantum simulation. We prepare a correlated state in a two-by-two tunnel-coupled Hubbard plaquette, demonstrating all the building blocks for realizing a programmable fermionic quantum simulator.
Exercising microscopic control over quantum systems is a central theme in modern physics. Neutral-atom quantum simulators leverage this control to explore quantum many-body phenomena by realizing paradigmatic Hamiltonians, such as the Hubbard model, in isolated systems. Advances in single-atom-resolved manipulation and detection have allowed measurements of microscopic correlations in strongly interacting quantum systems. Quantum gas microscopes have successfully approached this from the top down, starting from bulk quantum gases, while optical tweezers offer a complementary bottom-up route based on controlled few-particle systems. Combining these approaches opens a pathway towards assembling many-body systems atom by atom, enabling deterministic control over the initial quantum state. This thesis presents the development of a compact quantum gas microscope for programmable ensembles of fermionic lithium-6. The apparatus integrates laser cooling, magnetic field control, quantum-gas preparation, optical tweezers, projected potentials, and high-resolution imaging around a high-numerical-aperture microscope objective. Evaporative cooling in a crossed optical dipole trap produces degenerate two-component Fermi gases and molecular Bose--Einstein condensates, providing the quantum-degenerate reservoir for subsequent experiments. We demonstrate uniform loading of degenerate fermionic ensembles into programmable two-dimensional tweezer arrays, overcoming reservoir-size limitations by translating the tweezer array across the reservoir. Leveraging fermionic statistics and the resolved motional spectrum, we prepare a singlet pair in the three-dimensional motional ground state of each tweezer trap. Across an 8x8 array, this yields an average single-particle preparation fidelity of 98.47%. We develop a novel approach combining the deterministic preparation with spin- and site-resolved control via global magnetic field gradients and locally projected repulsive potentials to produce arbitrary product state configurations in parallel across all sites. In this way, we achieve programmable assembly of spin--charge product states of up to 128 atoms, with fast experimental cycle times of 3 seconds. Furthermore, we realize a new scheme for simultaneous spin-, site-, and density-resolved imaging of individual lithium-6 atoms. Encoding the spin information in the fluorescence polarization, we resolve the two spin components within a single 20 microsecond exposure, achieving detection fidelities exceeding 98.5%. These capabilities establish a fast route to preparing low-entropy fermionic product states with microscopic control over their initial spin, charge, and motional configuration. Coupling such states through optical lattices or tunnel-coupled tweezers provides a route for initializing far-from-equilibrium many-body systems, with applications to strongly correlated physics, quantum transport and thermalization, and fermionic quantum information processing.
Low-entropy arrays of atomic quantum systems in optical tweezers offer unique prospects for fundamental research on few- and many-body systems as well as for extended applications in quantum technology. The significance of this approach relies on the achievable system size, its uniformity, and the rate of qubit allocation. We propel the neutral-atom quantum-technology platform by the rapid assembly of a regular two-dimensional quantum register of up to 1024 atomic qubits, enabled by a novel implementation of intensity-homogenized tweezer arrays and parallelized atom transport. Our highly efficient microoptical architecture modularizes intensity equalization and tweezer patterning in separate functional units, eliminating restrictions that arise for high-power, high-resolution, and large-scale light-field control within a single device. Arrays of precise grid structure, trap depth, and vibrational frequency with more than 3500 sites are demonstrated. Individual sites are interconnected by up to 50 parallelized transport tweezers with intensity and position control in real-time for swift qubit relocation. Multi-tweezer transport enables the operation of target patterns of up to 32 x 32 sites with sustained near-unity filling fraction. These results boost neutral-atom quantum information science above the kiloqubit level.
Programmable arrays of ultracold atoms are a leading platform for quantum computation and simulation, enabling state-of-the-art implementations of quantum error correction, and analog simulations of Hubbard models that address open problems in condensed matter physics. In these systems, all local control is mediated through precisely shaped optical fields, and so the challenge of managing many-body quantum states becomes an exercise in optical design. In particular, one wishes for fast, flexible control with low disorder and heating, and access to large arrays with many atoms. An ideal optical system therefore must generate arbitrary patterns with high spatial resolution and low disorder, and alter these patterns on a timescale that is faster than the relevant atomic dynamics. Here, we present an optical system that is comparable to previous approaches in scale, while advancing all other axes. We demonstrate arbitrary pattern generation with 10−3 intensity resolution, a frame rate of >84 MFPS (megaframes per second), and a spatial resolution of 83×52 beam waists (with 11×52 waists accessible via a single 40 GHz electro-optic modulator). These capabilities unlock a new class of experiments. We develop and numerically validate a scheme for fully programmable Hubbard models, with time-dependent control over local chemical potentials, tunneling amplitudes, on-site interactions, and patterns of artificial magnetic flux. The same architecture performs fast, arbitrary permutations of tweezers in 2D, decoupling optical constraints from the design of high-rate error-correcting codes.
We report on the realization of a fast, scalable, and high-fidelity qubit architecture, based on 171 Yb atoms in an optical tweezer array.We demonstrate several attractive properties of this atom for its use as a building block of a quantum information processing platform.Its nuclear spin of 1=2 serves as a long-lived and coherent two-level system, while its rich, alkaline-earth-like electronic structure allows for low-entropy preparation, fast qubit control, and high-fidelity readout.We present a near-deterministic loading protocol, which allows us to fill a 10 × 10 tweezer array with 92.73(8)% efficiency and a single tweezer with 96.0(1.4)%efficiency.In the future, this loading protocol will enable efficient and uniform loading of target arrays with high probability, an essential step in quantum simulation and information applications.Employing a robust optical approach, we perform submicrosecond qubit rotations and characterize their fidelity through randomized benchmarking, yielding 5.2ð5Þ × 10 -3 error per Clifford gate.For quantum memory applications, we measure the coherence of our qubits with T Ã 2 ¼ 3.7ð4Þ s and T 2 ¼ 7.9ð4Þ s, many orders of magnitude longer than our qubit rotation pulses.We measure spin depolarization times on the order of tens of seconds and find that this can be increased to the 100 s scale through the application of a several-gauss magnetic field.Finally, we use 3D Raman-sideband cooling to bring the atoms near their motional ground state, which will be central to future implementations of two-qubit gates that benefit from low motional entropy.
The motion of atoms in programmable optical tweezer arrays offers many new opportunities for neutral atom quantum science. These include inter- and intra-site atom motion for resource-efficient implementations of fermionic and bosonic modes, respectively, as well as tweezer transport for efficient compilation of arbitrary circuits. However, the exploitation of atomic motion for all three purposes and others is limited by the inertia of the atoms. We present a comprehensive architectural blueprint for the use of fermionic metastable helium-3 (3He∗) atoms -- the lightest trappable atomic species -- in programmable optical tweezer arrays. This includes a concrete analysis of atomic structure considerations as well as Rydberg-mediated interactions. We show that inter-tweezer hopping of 3He∗ atoms can be ≳3× faster than previous demonstrations with lithium-6. We also demonstrate a new toolbox for encoding and manipulating qubits directly in the tweezer trap potential, uniquely enabled by the light mass of 3He∗. Finally, we provide several examples of new opportunities for fermionic quantum simulation and computation that leverage the transport and inter-tweezer hopping of 3He∗ atom arrays. These tools present new methods to improve the resource efficiency of neutral atom quantum science that may also enable quantum simulations of lattice gauge theories and quantum chemistry outside the Born-Oppenheimer approximation