PROGRAM has made substantial progress toward its two main objectives, delivering key theoretical and experimental advances in quantum simulation of lattice gauge theories (LGTs).
The first objective, scaling gauge-matter interactions beyond 1D, was successfully achieved through a collaborative effort with QuEra Computing and Harvard University. In this work, we implemented an analog quantum simulation of a U(1) lattice gauge theory with scalar matter in (2+1) dimensions using a Rydberg atom array arranged in a Kagome lattice. The experiment enabled the direct observation of string breaking in a two-dimensional gauge theory, a hallmark of confinement dynamics. The results were reported in a joint theory-experiment preprint [arXiv:2410.16558] demonstrating the viability of programmable neutral-atom arrays for exploring complex non-perturbative phenomena in high-energy physics.
The second objective, developing hardware-efficient digital quantum simulation strategies for gauge theories, advanced along two parallel lines. On one front, we formulated a framework for simulating non-Abelian lattice gauge theories using high-dimensional qudit encodings. We found schemes that significantly reduce the circuit complexity and leverage the intrinsic capabilities of atomic platforms. The corresponding experiment is now underway in Martin Ringbauer’s trapped-ion quantum computer in Innsbruck, targeting real-time dynamics of SU(2) gauge fields.
In parallel, we addressed the challenge of simulating fermionic matter in gauge theories by developing variational protocols for extended Fermi-Hubbard models based on ultracold fermionic atoms in optical lattices. These protocols are optimized for near-term quantum simulators and lay the foundation for incorporating fermionic matter into digital simulations of LGTs. These results were reported in a theory preprint [arXiv:2502.05067]. Ongoing work aims to extend these methods to full fermionic lattice gauge theories, further bridging high-energy theory and quantum simulation platforms.
These results represent a significant step forward in the realization of scalable, flexible, and hardware-aware quantum simulators of gauge theories, combining both analog and digital approaches.
