Observing and controlling macroscopic quantum systems has long been a driving force in quantum physics research. In particular, strong coupling between individual quantum systems and mechanical oscillators is being actively studied^1,2,3. Whereas both read-out of mechanical motion using coherent control of spin systems^4,5,6,7,8,9 and single-spin read-out using pristine oscillators have been demonstrated^10,11, temperature control of the motion of a macroscopic object using long-lived electronic spins has not been reported. Here we observe a spin-dependent torque and spin-cooling of the motion of a trapped microdiamond. Using a combination of microwave and laser excitation enables the spins of nitrogen–vacancy centres to act on the diamond orientation and to cool the diamond libration via a dynamical back-action. Furthermore, by driving the system in the nonlinear regime, we demonstrate bistability and self-sustained coherent oscillations stimulated by spin–mechanical coupling, which offers the prospect of spin-driven generation of non-classical states of motion. Such a levitating diamond—held in position by electric field gradients under vacuum—can operate as a ‘compass’ with controlled dissipation and has potential use in high-precision torque sensing^12,13,14, emulation of the spin-boson problem¹⁵ and probing of quantum phase transitions¹⁶. In the single-spin limit¹⁷ and using ultrapure nanoscale diamonds, it could allow quantum non-demolition read-out of the spin of nitrogen–vacancy centres at ambient conditions, deterministic entanglement between distant individual spins¹⁸ and matter-wave interferometry^16,19,20.

观察和控制宏观量子系统长期以来一直是量子物理学研究的驱动力。特别是，正在积极研究单个量子系统和机械振荡器之间的强耦合^1,2,3。^{而使用自旋系统4,5,6,7,8,9}的相干控制读取机械运动和使用原始振荡器进行单自旋读取已被证明^10,11，尚未报道使用长寿命电子自旋对宏观物体运动的温度控制。在这里，我们观察到被困微金刚石运动的自旋相关扭矩和自旋冷却。使用微波和激光激发的组合可以使氮空位中心的自旋作用于金刚石的取向，并通过动态反作用冷却金刚石的振动。此外，通过在非线性状态下驱动系统，我们证明了由自旋机械耦合激发的双稳态和自持相干振荡，这为自旋驱动产生非经典运动状态提供了前景。这种悬浮的钻石——在真空下通过电场梯度保持在适当的位置——可以作为具有受控耗散的“指南针”运行，并在高精度扭矩传感中具有潜在用途^12,13,14，模拟自旋玻色子问题¹⁵和探测量子相变¹⁶。在单自旋极限¹⁷并使用超纯纳米级金刚石，它可以允许在环境条件下对氮空位中心的自旋进行量子非破坏性读出，远距离单个自旋之间的确定性纠缠¹⁸和物质波干涉测量^{16,19 ,20} .