A quantum processor based on coherent transport of entangled atom arrays

Demonstrating the ability to shuttle ancilla arrays consisting of neutral atoms in optical tweezers, to realize a toric code state on a torus with 24 qubits. These results pave the way toward scalable quantum processing and enable new applications from simulation to metrology.

Impact: The ability to engineer parallel, programmable operations between desired qubits within a quantum processor is central for building scalable quantum information systems.

In our approach to building a scalable quantum information processor, qubits are transported to perform entangling gates with distant qubits, enabling programmable and nonlocal connectivity. Atom shuttling is performed using optical tweezers, with high parallelism in two dimensions and between multiple zones allowing selective manipulations.

Summary: In most approaches, qubits interact locally, constrained by the connectivity associated with their fixed spatial layout. Here, we demonstrate a new quantum processor with dynamic, nonlocal connectivity, using neutral atoms in optical tweezers, in which qubits are coherently transported in parallel in a planar configuration between single- and two-qubit operations. 
This architecture is used to realize various programmable entangled states such as the toric code state on a torus and to realize hybrid analog-digital evolution for quantum simulations.      

Contact: Mikhail D. Lukin, lukin@physics.harvard.edu

Focus area: QIS Technology

Institutions: Harvard, MIT, University of Innsbruck, and QuEra

Citation: D. Bluvstein et al., “A quantum processor based on coherent transport of entangled atom arrays”, Nature 604, 451–456 (2022).

Funding acknowledgment: We acknowledge financial support from the Center for Ultracold Atoms, the National Science Foundation, the Vannevar Bush Faculty Fellowship, the US Department of Energy (DE-SC0021013 and DOE Quantum Systems Accelerator Center, contract number 7568717), the Office of Naval Research, the Army Research Office MURI (grant number W911NF-20-1-0082) and the DARPA ONISQ program (grant number W911NF2010021).