Resonant driving for coherent quantum control of a ferromagnetic spin-1 BEC

Generation and manipulation of spin-squeezed quantum systems require versatile and precise control techniques. At the single-particle level, coherent control is typically achieved through Rabi and Ramsey protocols. In many-body interacting systems used for spin-squeezing experiments, however, interparticle interactions open additional pathways for control that extend beyond mean-field dynamics into the entangled regime. These include exploiting symmetry-breaking phase transitions as well as parametric and Floquet engineering methods. In this work, we demonstrate coherent excitation and control of collective many-body spin states in a ferromagnetic spin-1 Bose-Einstein condensate by directly harnessing intrinsic spin-dependent interactions. The resulting dynamics can be intuitively understood when mapped onto the physics of a driven harmonic oscillator.