Amination of the Gd@C(82) endohedral fullerene: tunable substitution effect on quantum coherence behaviors

The core–shell structure of endohedral fullerene-based anisotropic magnetic molecules of high spin with long coherence time could help scale up quantum systems. In this research, by amination of Gd@C(82) with morpholine, three derivatives are functionalized with 5, 7 and 9 morpholine groups providing an interesting model to investigate the relationship between the quantum coherence and the spin environment. The original radical located on the carbon cage is successfully quenched, affording a quantum phase memory times (T(M)) over 5 μs at 5 K. By increasing the number of substitution groups, spin–lattice relaxation times (T(1)) also show significant enhancement due to the interaction variation between the molecules and the environments. We found that the T(M) of the three molecules show no obvious difference below 10 K, while they are limited by T(1) at higher temperatures. In this work, the variable functional groups are able to tune both T(1) and T(M), offering the possibility for application of high-spin magnetic molecules in the field of quantum information processing.