Addressable Control of Hybrid Spin Qubit in Single-Atom Copper-Modified Fullerene

Developing high-dimensional solid-state quantum technologies requires overcoming the trade-off between spin dimensionality and quantum coherence. Hybrid spin architectures offer a promising solution to expand the quantum state space bottom-up by combining rapid electronic manipulation with robust nuclear phase memory. However, solid-state hybrid spin materials capable of simultaneously supporting both electron and nuclear spin manipulations remain exceedingly rare. Here, we report a Cu2+ (S = 1/2, I = 3/2) hybrid spin system dispersed in a magnetically silent C60 matrix, in which we not only demonstrate comprehensive coherent control over both electron and nuclear spin degrees of freedom but also strike a balance between spin dimensionality and coherence time. The pristine carbon environment suppresses surrounding magnetic noise, acting in tandem with dynamical decoupling to prolong the electron spin coherence time to 16.16 μs. Simultaneously, the nuclear quadrupole interaction of Cu2+ breaks the degeneracy of the nuclear spin manifold, enabling precise addressability of an eight-dimensional Hilbert space. Furthermore, strong electron–nuclear hyperfine coupling acts as a powerful lever, accelerating the nuclear spin Rabi frequency by a factor of 17. By achieving the coexistence of a large manifold of addressable levels and long-lived quantum coherence, Cu/C60 provides a high-dimensional hybrid spin node and a compelling bottom-up approach to expanding the quantum state space.