ALP Seminar: Scalable Qubit Arrays for Quantum Computation and Optimisation

Quantum computation offers a revolutionary approach to how information is processed, offering new applications in material design, quantum chemistry and speed up of real-world optimisation problems, however, a large number of qubits are required to obtain quantum advantage over classical hardware. Neutral atoms are an excellent candidate for practical quantum computing, enabling large numbers of identical qubits to be cooled and trapped, overcoming major barriers to scaling experienced by competing architectures. A crucial ingredient for quantum computing is the ability to perform controlled two-qubit gate operations, for which the strong, long-range dipole-dipole interaction between Rydberg atoms can be exploited to implement deterministic gate operations between atoms within a radius of R < 10 μm.

We present progress towards a new experimental platform for quantum computation at the University of Strathclyde, supported by the EPSRC Prosperity Partnership with M Squared Lasers, based on reconfigurable atom arrays of up to 225 Cs atoms. We demonstrate high fidelity single qubit gate operations with errors below the threshold for fault tolerance using a non-destructive readout technique, along with work towards simultaneous trapping of arrays of ground and Rydberg states as the first step to creating a scalable architecture for quantum computing. These results pave the way towards performing high-fidelity two qubit and multi-qubit gate operations using a novel adiabatic rapid passage protocol developed at Strathclyde, as well as exploring applications of the neutral atom system to solving classical optimisation problems.