Experimental Quantum Optics
and Photonics Group


Latest News

Demonstration of weighted graph optimization on a Rydberg atom array using local light-shifts
Neutral atom arrays have emerged as a versatile platform towards scalable quantum computation and optimisation. In this paper we present first demonstrations of weighted graph optimization on a Rydberg atom array using annealing with local light-shifts. We verify the ability to prepare weighted graphs in 1D and 2D arrays, including embedding a five vertex non-unit disk graph using nine physical qubits. We find common annealing ramps leading to preparation of the target ground state robustly over a substantial range of different graph weightings. This work provides a route to exploring large-scale optimisation of non-planar weighted graphs relevant for solving relevant real-world problems. For more details see arXiv:2404.02658.
Benchmarking the algorithmic performance of near-term neutral atom processors
We have performed theoretical work on algorithmic benchmarking to evaluate the performance of near-term neutral atom processors accounting for realistic gate errors and atom loss. We show that for a 9 qubit system a quantum volume of 29 is attainable, the maximum possible for this size of processor, highlighting the viability of using near-term neutral atom hardware for small-scale algorithms. For more details see arXiv:2402.02127.
Commensurate and incommensurate 1D interacting quantum systems
We use dynamically varying microscopic light potentials in a quantum-gas microscope to study commensurate and incommensurate 1D systems of interacting bosonic atoms in an optical lattice Nat Communications 15, 474 (2024).
Interspecies Förster resonances of Rb-Cs Rydberg d-states for enhanced multi-qubit gate fidelities
We present an analysis of interspecies interactions between Rydberg d-states of rubidium and cesium. We identify the Förster resonance channels offering the strongest interspecies couplings, demonstrating the viability for performing high-fidelity two- and multi-qubit CkZ gates up to k=4, including accounting for blockade errors evaluated via numerical diagonalization of the pair-potentials. Our results show d-state orbitals offer enhanced suppression of intraspecies couplings compared to s-states, making them well suited for use in large-scale neutral atom quantum processors. For more details see arXiv:2401.02308.

Recent publications

Spontaneously Sliding Multipole Spin Density Waves in Cold Atoms
Physical Review Letters 132, 143402 (2024)
We report on the observation of spontaneously drifting coupled spin and quadrupolar density waves in the ground state of laser driven …
Interspecies Förster resonances for Rb-Cs Rydberg d-states for enhanced multi-qubit gate fidelities
Physical Review Research 6, 013293 (2024)
Benchmarking the algorithmic performance of near-term neutral atom processors
(2024)
Neutral atom quantum processors provide a viable route to scalable quantum computing, with recent demonstrations of high-fidelity and …
Demonstration of quantum-enhanced rangefinding robust against classical jamming
Optics Express 32, 2916 (2024)
We demonstrate a quantum-enhanced lidar capable of performing confident target detection and rangefinding in the presence of strong, …
Demonstration of weighted graph optimization on a Rydberg atom array using local light-shifts
(2024)
Neutral atom arrays have emerged as a versatile platform towards scalable quantum computation and optimization. In this paper we …