Vibrational Molecular Magnetism

The recent surge of interest in chiral phonons – vibrational modes carrying angular momentum – brings renewed attention to the coupling between magnetism and atomic or molecular motion. While current studies primarily focus on bulk materials, molecular systems offer an ideal, well-controlled platform for exploring analogous phenomena on the microscopic scale. We conduct a detailed and theoretically rigorous investigation of molecular vibrational magnetism, arising from the coupling between nuclear motion and magnetic moments.

Experimental observations and theoretical descriptions of rotational and vibrational magnetism in molecules date back more than half a century, primarily to the golden era of microwave spectroscopy. Yet, a unified and quantitative theoretical framework for spin-vibration interactions has remained elusive. Using modern ab initio methods and analytic models to derive the relevant coupling parameters, we have re-visited this long-standing problem and predict localized, vibrationally induced magnetic fields.

While our present study focuses on nuclear spin-vibration interactions, the same framework may be extended to analogous effects involving electron spin degrees of freedom, offering a fresh perspective on the currently emerging field of chiral phononics.