Real-Time Dynamics in a (2+1)-D Gauge Theory: The Stringy Nature on a Superconducting Quantum Simulator
by
Understanding the precise confinement mechanism across different gauge theories and the degree of universality of related string-like descriptions of confining flux tubes is challenging in modern physics. This talk presents an experimental quantum simulation of a (2+1)-D gauge theory on a superconducting quantum chip with up to 146 qubits, quantum circuits with up to 180 two-qubit gates depth, and up to a total of 66960 two-qubit gates, allowing for the direct observation and manipulation of its fundamental electric strings in real time. We describe an optimized embedding of the Z2-Higgs model (Z2HM) Hamiltonian into a superconducting-circuit heavy-hexagonal architecture, which directly mimics the matter -vertices- and gauge -links- degrees of freedom, and integrate error suppression, mitigation, and correction techniques, enhanced by the local symmetries of these models, to push the frontier of current experimental capabilities and provide quantitative tests of the stringy nature of the model. Due to the large-scale quantum simulation, we observe the periodic longitudinal compression and stretching of the string, as well as a transversal bending localized to the charged string endpoints as a precursor of the rotation of a rigid string, all dependent on the back-reaction of the dynamical matter fields in real-time. In all the simulations, we run 300000 shots per circuit, that is, 600000 shots per time instant. Exploiting the flexibility of our approach, we also discuss multi-string phenomena, showing how strings can fragment and recombine. This work opens a new avenue for superconducting quantum simulation to probe the non-perturbative dynamics of gauge theories, bridging the gap between theoretical constructs and observable string phenomena.
Based on work with Jesus Cobos, Joana Fraxanet, Cesar Benito Lamata, Francesco di Marcantonio, Pedro Rivero, Kornel Kapas, Miklos Antal Werner, Ors Legeza, Alejandro Bermudez, Enrique Rico (arXiv:2506.xxxxx to appear).
