A Generalized Open Quantum System Approach for the Electron Paramagnetic Resonance of Magnetic Atoms

A recent experimental breakthrough allowed to probe electronic parametric resonance of a single magnetic atom in an STM setup. The results present intriguing features, such as an asymmetric lineshape and unusually large ratio of the decoherence and decay rates, which defy standard approaches using the conventional Bloch equations. To address these issues we employ novel generalized Bloch equations, together with proper microscopic modeling of the magnetic adatom, and show how all the experimental features can naturally be accounted for. The proposed approach may also be useful in treating any future similar experiments, as well as next generation hybrid quantum devices.