Quantum simulation of spin models with tunable atom arrays
Final Report Abstract
The goal of the project was to realise a scalable quantum simulator with long-range interactions using neutral atoms. Our experimental platform allows for trapping and sorting individual atoms into deterministic one-dimensional patterns using arrays of optical tweezers. We developed a laser system to drive Rydberg excitations, thereby introducing strong, coherent interactions between atoms across several sites. With these tools in place, we observed coherent dynamics of Rydberg excitations and could study the Rydberg blockade mechanism under very controlled conditions. Furthermore, we implemented an adiabatic protocol to evolve the system from all atoms being in their electronic ground state to ordered Rydberg crystals breaking different spatial symmetries. This new approach of performing quantum simulations was picked up by several news outlets, e.g. https://news.harvard.edu/gazette/story/2017/11/researchers-create-new-type-ofquantum-computer/. The high degree of control over such a quantum many-body system enabled new discoveries. By knocking the system out of equilibrium, we also observed surprisingly long-lived manybody oscillations that challenged our intuition about thermalisation in our system. Here, we had a system that should generically thermalise from an out-of-equilibrium setting, yet seemed to persist in its state much longer than anticipated. This sparked a lot of theoretical interest and a new interpretation in terms of quantum many-body scars. In the meantime, we learned how important the coherence properties of the Rydberg lasers are for the fidelity of quantum operations. By addressing limitations of our system could boost the coherence and observe high-fidelity entanglement between neighbouring atoms, which showed that neutral atoms are possibly good candidates for quantum information processing applications. With these capabilities in place, we have a powerful platform for studying various spin models, large-scale entanglement, quantum optimisation, and dynamics of many-body systems in regimes where numerical simulations are not feasible.
Publications
- ”Probing many-body dynamics on a 51-atom quantum simulator” - Nature 551, 579 (2017)
H. Bernien, S. Schwartz, A. Keesling, H. Levine, A. Omran, H. Pichler, S. Choi, A. S. Zibrov, M. Endres, M. Greiner, V. Vuletić, M. D. Lukin
(See online at https://doi.org/10.1038/nature24622) - ”High-fidelity control and entanglement of Rydberg atom qubits” - Phys. Rev. Lett. 121, 123603 (2018)
H. Levine, A. Keesling, A. Omran, H. Bernien, S. Schwartz, A. S. Zibrov, M. Endres, M. Greiner, V. Vuletić, M. D. Lukin
(See online at https://doi.org/10.1103/PhysRevLett.121.123603) - ”Probing quantum critical dynamics on a programmable Rydberg simulator”. Nature 568, 207 (2019)
A. Keesling, A. Omran, H. Levine, H. Bernien, H. Pichler, S. Choi, R. Samajdar, S. Schwartz, P. Silvi, S. Sachdev, P. Zoller, M. Endres, M. Greiner, V. Vuletić, M. D. Lukin
(See online at https://doi.org/10.1038/s41586-019-1070-1) - ”Schreiben und Rechnen mit Atomen: Atomketten als Quantensimulatoren und -computer” - Physik in unserer Zeit 49, 220 (2018)
H. Bernien, A. Omran
(See online at https://doi.org/10.1002/piuz.201801516)
