Collective dissipation and parameter sensitivity in trapped ions coupled to a common thermal reservoir
Phys. Rev. A 113, 053105 – Published 8 May, 2026
DOI: https://doi.org/10.1103/h1fh-83td
Abstract
We investigate the dynamics of two trapped ions interacting with a common thermal reservoir, focusing on how cross-correlated dissipation influences heating, steady-state behavior, and parameter sensitivity. Starting from a microscopic system-reservoir model, we derive the corresponding Heisenberg-Langevin equations and show that reservoir-induced correlations generate collective decay channels and, when the cross-damping rate matches the local damping, a decoherence-free normal mode that preserves memory of the initial excitations. Using the Fisher information associated with motional population measurements, we identify the parameter regimes in which cross-damping enhances the estimability of both system and reservoir properties. For nonclassical initial states, we also show that reservoir-mediated correlations can generate or maintain entanglement, with the strongest effects occurring near the decoherence-free condition.
