[Atomic physics seminar] Entanglement-assisted readout and cooling of neutral atom qubits in an optical tweezer array

Speaker: Dr Lewis Picard, Caltech, USA

Title: Entanglement-assisted readout and cooling of neutral atom qubits in an optical tweezer array

Abstract:
Neutral atoms held in optical tweezers have emerged as a powerful platform for quantum computing, simulation, and metrology. Internal electronic or hyperfine states of atoms can be used to encode qubits, which can be controllably entangled by exciting the atoms to high energy Rydberg states. However, achieving fast, high-fidelity readout and loss detection of atomic qubits remains a challenge, as direct fluorescence imaging of the atoms often leads to heating and eventual atom loss. We demonstrate indirect readout of strontium-88 qubits in an optical tweezer array via high-fidelity entanglement with ancilla atoms. We show that this approach can be used to increase readout fidelity through repeated measurements, as well as enabling coherence-preserving qubit loss detection. Finally, we explore algorithmic cooling of atoms in optical tweezers, in which the motional entropy of data qubits is coherently transferred to the electronic state of an ancilla. These methods represent a comprehensive, species-agnostic toolbox for ancilla-assisted detection and state preparation in neutral atom experiments.