Impact of Spin-Orbit Coupling in the spin relaxation of potential molecular spin qubits studied by x-ray absorption spectroscopy

Molecular magnets constitute one of most promising systems to be implemented in future quantum technologies. To achieve real applications, it is crucial to increase their spin-spin coherence times (T2), which are strongly correlated to spin-phonon relaxation times (T1) that have a direct dependence on the spin-orbit coupling (SOC) in the molecule. Therefore, a comprehensive study of the SOC in monoelectronic molecular systems, and their subsequent control, is essential to improve their performance as potential building blocks for quantum information technologies. In order to achieve this, we propose to perform X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements in octahedral low-spin Fe(III) and Cr(III) compounds, which will allow us to characterize their different degree of SOC and its effect in quantum relaxation phenomena.