APIQuL - Attosecond Photoelectron Imaging with Quantum Light

This project integrates quantum optics into ultrafast imaging, bridging quantum optics, attosecond science, and photochemistry. It aims to refine photoelectron momentum distributions, enhance holographic resolution, and improve control over quantum coherence in electron motion. Selectively enhancing quantum features like entanglement and non-classical correlations could unlock new opportunities in attochemistry and quantum technologies. It involves UCL, Stanford and the University of Arizona, among other institutions and it is part of the NSF/UKRI Quantum Information in Chemistry joint programme (for details see https://gtr.ukri.org/projects?ref=UKRI2300). I am the PI in the UK, Alessio Serafini the Co-I and we are working closely with Phil Bucksbaum's and Mohammed Hassan's experimental groups. We are also working with many other researchers and groups across the globe.

The project has started in October/November 2025, has been a steep learning curve for us, and is already bearing fruit. Our first results were presented in conferences and there are preprints too! Below you will see the first onsite meeting, in late June 2026.

APIQuL collaboration. From left to right: Alessio Serafini (UCL), Gurpahul Singh (Perimeter Institute), Thomas Rook (UCL), Mohammed Hassan (Arizona), Javier Rivera-Dean (UCL), Phil Bucksbaum (Stanford), Marcelo Ciappina (Technion Guandong), Carla Faria (UCL), Jiakang Chen (UCL), Sufia Hashim (UCL), Paris Tzallas (Heraklion). Other participants (not in the picture) are Maciej Lewenstein and Philipp Stammer, both from ICFO.

There will be a website coming soon! Below you will see we have been quite active.

Journal publications

• J. Rivera-Dean, L. Petrovic, M. Lewenstein, and P. Stammer, “Attosecond quantum optical interferometry,” Reports on Progress in Physics 89, 047901 (2026).

• J. Rivera-Dean, D. Kanti, P. Stammer, S. Carlström, N. Tsatrafyllis, M. Yu. Ivanov, M. Lewenstein, and P. Tzallas, “Propagation effects in high harmonic generation media driven by bright squeezed vacuum light,” Nature Communications 17, 8457 (2026).

• J. Chen, S. Hashim, and C. F. de M. Faria, “Physics-informed neural networks for solving saddle-point equations in strong-field physics with tailored fields,” Physical Review Research 8, 033029 (2026).

• D. Habibović and D. B. Milošević, “Intensity-dependent enhancements in strong-field ionization by quantum light,” Physical Review A 112, L051103 (2025).

Preprints

• M. Sennary, J. Rivera-Dean, Y. Wange, M. Lewenstein, and M. T. Hassan, “Attosecond quantum optics” (2026). arXiv:2601.08671https://doi.org/10.48550/arXiv.2601.08671

• P. Stammer, J. Rivera-Dean, E. Pisanty, and M. Lewenstein, “Attosecond metrology of bright quantum light” (2026). arXiv:2607.06395https://doi.org/10.48550/arXiv.2607.06395

• J. Rivera-Dean, M. Even-Tzur, M. F. Ciappina, C. Granados, O. Cohen, and P. Stammer, “Emergence of Gaussian entanglement and non-Gaussianity in high-harmonic generation driven by bright squeezed light” (2026). arXiv:2606.22714https://doi.org/10.48550/arXiv.2606.22714

• J. Rivera-Dean, T. Rook, G. Singh, P. Stammer, M. Khokhlova, E. Pisanty, and C. F. de M. Faria, “Erasing photons from bright squeezed vacuum light via above-threshold ionization” (2026). arXiv:2605.31160https://doi.org/10.48550/arXiv.2605.31160

• P. Stammer, J. Rivera-Dean, D. Kim, A. Chacón, W. Gao, and C. Granados, “Symmetry breaking by quantum light in solid-state high-harmonic generation” (2026). arXiv:2605.28236https://doi.org/10.48550/arXiv.2605.28236

• G. Singh, T. Rook, J. Rivera-Dean, and C. F. de M. Faria, “Interferometrically enhanced asymmetry in strong-field ionization with bright squeezed vacuum” (2026). arXiv:2604.12646https://doi.org/10.48550/arXiv.2604.12646

• P. Stammer, C. Granados, and J. Rivera-Dean, “Fluctuation-induced symmetry breaking in high harmonic generation for bicircular quantum light” (2026). arXiv:2603.24377https://doi.org/10.48550/arXiv.2603.24377

Conference presentations and papers

• M. T. Hassan, “Attosecond Quantum Optics,” Atto-FEL, University College London (2026).

• H. Ma, C. Cheng, I. Gabalski, A. Ghrist, J. Ohara, J. Rivera-Dean, G. Singh, T. Rook, E. Weckwerth, M. Hassan, C. F. de M. Faria, and P. Bucksbaum, “Two-Color Strong-Field Ionization with Non-Classical Light,” DAMOP 2026, Providence, RI (2026).https://meetings-archive.aps.org/damop/2026/g05/3/

• P. K. Bangal and N. Golubev, “Ultrafast Charge Migration in Molecules Placed in Strong Field Cavity,” DAMOP 2026, Providence, RI (2026).https://meetings-archive.aps.org/damop/2026/g05/4/