Entanglement of Spin-Pair Qubits with Intrinsic Dephasing Times Exceeding a Minute

Understanding and protecting the coherence of individual quantum systems is a central challenge in science technology. Over last decades, rich variety methods to extend have been developed. A complementary approach look for naturally occurring that are inherently protected against decoherence. Here, we show pairs identical nuclear spins solids form intrinsically long-lived systems. We study three carbon-13 diamond realize high-fidelity measurements their states using single NV center vicinity. then reveal spin robust external perturbations due unique combination phenomena: clock transition, decoherence-free subspace, variant on motional narrowing. The resulting inhomogeneous dephasing time $T_2^* = 1.9(3)$ minutes, longest reported individually controlled qubits. Finally, develop complete control an entangled state between two spin-pair qubits through projective parity measurements. These abundantly present other solids, provide new opportunities sensing, information processing, networks.