Manipulation of Molecular Qubits by Isotope Effect on Spin Dynamics

Controlling spin behavior via external stimuli is a key route to develop molecular spintronics devices. Photons, temperature, pressure, chemicals, and electric field are the possible stimuli. Herein, we report a new method, the isotope effect, to control spin behavior in molecule magnet systems. It can not only control the relaxation of magnetization, but also regulate the spin lifetime of quantum coherence. In this regard, we found a couple of low-spin Co(II) complexes, {[CoL](CH3CN)}[BPh4](2) center dot CH3CN (1-H; L = 1,5-bis(2pyridylmethyl)-1,5-diazacyclooctane) and its deuterated analog {[CoL](CD3CN)) [BPh4](2)center dot CD3CN (1-D), exhibiting the rare ON/OFF switching of double spin relaxation behaviors in magnetic relaxation as well as the regulation of spin lifetime in quantum coherence at low temperatures. We discuss the mechanisms underlying the formation and the relevance of intramoleculer vibration modes, which give the direct experimental evidence of spin-intramolecular vibration coupling, and also provide new guidance for the ultrafast and electrical control of spin behaviors.

Automated summary

Controlling spin behavior in magnetic complexes via the isotope effect can regulate magnetization relaxation and quantum coherence spin lifetime, offering new insights for the development of spintronics devices.