Extensive work on single molecule magnets has identified a fundamental mode of relaxation arising from the nuclear-spin assisted quantum tunnelling of nearly independent and quasi-classical magnetic dipoles. Here we show that nuclear-spin assisted quantum tunnelling can also control the dynamics of purely emergent excitations: magnetic monopoles in spin ice. Our low temperature experiments were conducted on canonical spin ice materials with a broad range of nuclear spin values. By measuring the magnetic relaxation, or monopole current, we demonstrate strong evidence that dynamical coupling with the hyperfine fields bring the electronic spins associated with magnetic monopoles to resonance, allowing the monopoles to hop and transport magnetic charge. Our result shows how the coupling of electronic spins with nuclear spins may be used to control the monopole current. It broadens the relevance of the assisted quantum tunnelling mechanism from single molecular spins to emergent excitations in a strongly correlated system.

对单分子磁体的大量研究已经确定了一种基本的弛豫模式，该模式是由核自旋辅助的几乎独立且准经典的磁偶极子的量子隧穿引起的。在这里，我们证明了核自旋辅助量子隧穿也可以控制纯涌出激发的动力学：自旋冰中的磁单极子。我们的低温实验是在具有广泛核自旋值的标准自旋冰材料上进行的。通过测量磁弛豫或单极电流，我们证明有力的证据表明，与超精细场的动态耦合会使与磁单极子相关的电子自旋共振，从而使单极子跳跃并传输电荷。我们的结果表明，电子自旋与核自旋的耦合如何可用于控制单极电流。它扩展了辅助量子隧穿机制从单分子自旋到强相关系统中出现的激发的相关性。