Universal quantum information processing for tweezer clocks

We demonstrate a fully programmable universal quantum processor using optical clock qubits based on strontium-88 atoms trapped in optical tweezers. We simultaneously realize several key tasks: motional ground state preparation, site-selective mid-circuit readout, and high-fidelity entanglement generation on optical qubits. As a first step, we implement a novel cooling method involving detection and correction of excited atomic motional states, reminiscent of Maxwell's demon thought experiment. Next, facilitated by the low-entropy initial state and motional state control, we demonstrate site-selective mid-circuit detection and hyper-entanglement of the motional and spin degrees of freedom. In parallel, we utilize high-fidelity entangling gates mediated by Rydberg interactions for preparation of metrologically useful states. Gaining access to this expanded toolbox, we implement ancilla-assisted algorithms designed to improve quantum metrology. Finally, we propose a hybrid platform that could potentially improve the performance of tweezer clocks.