Magnetic Co-tip control of quantum states in a triple-decker sandwich molecule: Mechanistic insights from DFT/HEOM simulations

The manipulation of quantum states in triple-decker organometallic molecules remains challenging due to their complex many-body interactions. In this study, we combine density functional theory (DFT) and the hierarchical equations of motion (HEOM) to map, for the first time, the evolution of quantum states in a triple-decker dinuclear complex under mechanical manipulation by a magnetic cobalt tip. DFT calculations demonstrate that the tip approach induces substantial structural distortion of the molecular framework, which triggers a reconstruction of the internal magnetic coupling network. This process is accompanied by an evolution of the electronic structure that includes modifications to the local density of states, magnetic moment, spin-state populations, and molecular orbital hybridization characteristics. By solving the spin-polarized Anderson model using the HEOM method, we have revealed the dynamic evolution of strongly correlated Kondo effects. When the system enters the contact regime, the Kondo resonance peak exhibits asymmetric splitting, where the splitting characteristics exhibit a simultaneous dependence on the spin polarization degree of the electrodes and the coupling strength between the impurity and the electrodes. These atomic-scale insights into the external control of molecular quantum states provide a robust framework for the future design of molecular spintronic devices.