ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT ttk.bme.hu>]

Meghívó

BME Elméleti Fizika Szeminárium,

szept. 12. péntek 10h15,
1111 Bp., Budafoki út 8., BME FIII. magasföldszint 1, szemináriumi szoba

Werner Miklós (HUN-REN Wigner RCP):
Real-Time Dynamics in a (2+1)-D Gauge Theory: The Stringy Nature on a
Superconducting Quantum Simulator

Understanding the confinement mechanism in gauge theories and the
universality of effective string-like descriptions of gauge flux tubes
remains a fundamental challenge in modern physics. We probe string modes of
motion with dynamical matter in a digital quantum simulation of a (2+1)
dimensional gauge theory using a superconducting quantum processor with up
to 144 qubits, stretching the hardware capabilities with quantum-circuit
depths comprising up to 192 two-qubit layers. We realize the $Z_2$-Higgs
model ($Z_2$HM) through an optimized embedding into a heavy-hex
superconducting qubit architecture, directly mapping matter and gauge
fields to vertex and link superconducting qubits, respectively [1]. Using
the structure of local gauge symmetries, we implement a comprehensive suite
of error suppression, mitigation, and correction strategies to enable
real-time observation and manipulation of electric strings connecting
dynamical charges. Our results resolve a dynamical hierarchy of
longitudinal oscillations and transverse bending at the endpoints of the
string, which are precursors to hadronization and rotational spectra of
mesons. We further explore multi-string processes, observing the
fragmentation and recombination of strings. The experimental results are
compared against extensive tensor network simulations. The ground state
phase diagram of the $Z_2$ Higgs model has been analyzed by the density
matrix renormalization group (DMRG), while the recently introduced "basis
update and Galerkin" method has been used to predict large-scale real-time
dynamics and validate our error-aware protocols [2]. This work establishes
a milestone for probing non-perturbative gauge dynamics via superconducting
quantum simulation and elucidates the real-time behavior of confining
strings [1].

[1] J. Cobos, J. Fraxanet, C. Benito, F. di Marcantonio, P. Rivero, K.
Kapás, M. A. Werner, Ö. Legeza, A. Bermudez, and E. Rico, arXiv:2507.08088
(2025).
[2] Gianluca Ceruti, Christian Lubich, and Dominik Sulz, SIAM Journal on
Numerical Analysis 61, 194-222 (2023).

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor