Stability and Decay of Macrovortices in Rotating Bose Gases Beyond Mean Field

We study the formation, stability, and decay of macrovortices in a rotating Bose gas confined by a Mexican-hat potential with a multiconfigurational ansatz. By systematically including correlations beyond the mean-field level, we map the equilibrium phase diagram and identify regimes of coexistence between vortex lattices and multiply charge central vortices. Quench dynamics reveals that macrovortices are robust under changes in rotation or interaction strength, sustaining clean monopole oscillations with well-separated, vorticity-dependent breathing frequencies. In contrast, trap quenches trigger a universal decay process mediated by vortex-phonon coupling, in which rotational energy is progressively transferred to compressible modes until the macrovortex splits into singly quantized vortices. Our results demonstrate that macrovortex lifetimes and decay pathways can be tuned by trap confinement, providing experimentally accessible signatures of vortex-phonon interactions and collective energy transfer in correlated quantum fluids.