Efficient state preparation for the Schwinger model with a theta term

• DOI: 10.1103/physrevd.111.074515
• Publication Date: 2025-04-24T14:13:05Z
• Authors: Alexei Bazavov; Brandon Henke; Leon Hostetler; Dean Lee; Huey-Wen Lin; Giovanni Pederiva; Andrea Shindler

We present a comparison of different quantum state preparation algorithms and their overall efficiency for the Schwinger model with theta term. While adiabatic is proved to be effective, in practice it leads large gate counts prepare ground state. The approximate optimization algorithm (QAOA) provides excellent results while keeping small by design, at cost an expensive classical minimization process. introduce “blocked” modification Hamiltonian used QAOA that further decreases length as size problem increased. rodeo (RA) powerful tool efficiently any eigenstate Hamiltonian, long its overlap initial guess enough. obtain best when combining blocked ansatz RA, this relatively short without need perform steps sizes. Published American Physical Society 2025