2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/23547We have observed multiphoton transitions between two macroscopic quantum-mechanical superposition states formed by two opposite circulating currents in a superconducting loop with three Josephson junctions. Resonant peaks and dips of up to three-photon transitions were observed in spectroscopic measurements when the system was irradiated with a strong RF-photon field. The widths of the multiphoton absorption dips are shown to scale with the Bessel functions in agreement with theoretical predictions derived from the Bloch equation or from a spin-boson model.4 pages, 3 figuresMesoscale and Nanoscale PhysicsSuperconductivitytext