Atom quantum computing in a 2D neutral Cs array

We present the implementation of quantum circuits performed on a lattice of neutral atom qubits. Atoms are loaded into a blue-detuned optical lattice constructed from cross-hatched lines which form optical traps. Atomic rearrangement using optical tweezers is used to deterministically load atoms into targeted sites. Single site quantum gates are performed using resonant microwaves and site selective Stark shifts. Controlled-Z gates are performed using two photon Rydberg excitations. Using this universal gate set, we create large entangled states and demonstrate a variety of multi-qubit quantum algorithms.

We create GHZ states with >6 qubits encoded on long lived hyperfine ground state qubits and measure their coherence times. We demonstrate phase estimation and apply this algorithm to solve a quantum chemistry problem. We also demonstrate two different hybrid quantum and classical optimization algorithms. We present results using the variational quantum eigensolver algorithm to estimate ground state energies of the Lipkin Hamiltonian. We also present results of the quantum approximate optimization algorithm applied to find the maximum cut of several graphs.