Controlling Entanglement for Enhanced Dense Coding in Anisotropic Floquet‐Driven Two‐Qutrit System

ABSTRACT High‐dimensional quantum systems offer a promising pathway to exceed information capacity limits, yet realizing robust dense coding remains challenged by decoherence. While Floquet engineering allows dynamic control, its potential in high‐spin systems is not fully exploited. Here, presenting a novel integration of periodic driving with higher‐dimensional thermal spin models, we investigate the dense coding capacity of a two‐qutrit Heisenberg XXZ system with single‐ion anisotropy. By deriving an effective Hamiltonian, we analyze the effect of the external driving parameters on the system's quantum resources. We demonstrate capacity modulation via the Floquet driving ratio, where renormalization factor zeros induce dynamical decoupling, suppressing quantum advantage. Crucially, negative single‐ion anisotropy amplifies quantum efficiency gain to approximately 95% relative to the classical limit, offering resilience against thermal fluctuations. Furthermore, we numerically demonstrate a monotonic, nonlinear parametric dependence between capacity and negativity, revealing a critical entanglement threshold required to surpass the classical Holevo bound. These results provide a blueprint for designing tunable, high‐capacity quantum channels, highlighting anisotropy as a pivotal control parameter.