Physical devices operating out of equilibrium are affected by thermal fluctuations, limiting their operational precision. This issue is particularly pronounced at microscopic and quantum scales, where its mitigation requires additional entropy dissipation. Understanding this constraint is important for both fundamental physics and technological design. Clocks, for example, need a thermodynamic flux towards equilibrium to measure time, resulting in a minimum entropy dissipation per clock tick. Although classical and quantum models often show a linear relationship between precision and dissipation, the ultimate bounds on this relationship remain unclear. Here we present an autonomous quantum many-body clock model that achieves clock precision that scales exponentially with entropy dissipation. This is enabled by coherent transport in a spin chain with tailored couplings, where dissipation is confined to a single link. The result demonstrates that coherent quantum dynamics can surpass the traditional thermodynamic precision limits, potentially guiding the development of future high-precision, low-dissipation quantum devices.

在失衡状态下运行的物理设备会受到热波动的影响，从而限制其运行精度。这个问题在微观和量子尺度上尤为明显，因为要缓解这个问题，需要额外的熵耗散。了解这个约束对于基础物理学和技术设计都很重要。例如，clocks 需要一个趋向平衡的热力学通量来测量时间，从而在每个 clock tick 的熵耗散最小。尽管经典模型和量子模型通常显示精度和耗散之间的线性关系，但这种关系的最终界限仍然不清楚。在这里，我们提出了一个自主量子多体时钟模型，它实现了随熵耗散呈指数级扩展的时钟精度。这是通过具有定制耦合的自旋链中的相干传输实现的，其中耗散仅限于单个链节。结果表明，相干量子动力学可以超越传统的热力学精度极限，有可能指导未来高精度、低耗散量子器件的开发。