论文标题
海森贝格限制的计量学，对探针配置有一致的控制
Heisenberg-limited metrology with coherent control on the probes' configuration
论文作者
论文摘要
量子计量学的一个主要特征是海森堡缩放的可能性，这是对经典统计范围的二次改进。然而，众所周知，这种缩放是噪音的脆弱。对于某些噪声类型，可以通过误差校正来恢复，但对于其他重要类型（例如Dephasing），海森堡缩放率似乎是明显丢失的。在这里，我们表明，如果实验者有能力在替代配置的连贯叠加中探测物理过程，则有时可以提高这种限制。作为一个具体的例子，我们考虑了存在随机相位踢的相位估计问题，在正常条件下，该问题已知可以防止海森贝格缩放。我们提供了一个并行的方案，该方案可实现有关探针能量的缩放，以及相对于总探测时间实现海森贝格缩放的顺序协议。此外，我们表明，在存在连续的时间去降低噪声的情况下，还可以通过将路径的叠加与快速控制操作相结合，也可以实现Heisenberg缩放量的频率估计。
A central feature of quantum metrology is the possibility of Heisenberg scaling, a quadratic improvement over the limits of classical statistics. This scaling, however, is notoriously fragile to noise. While for some noise types it can be restored through error correction, for other important types, such as dephasing, the Heisenberg scaling appears to be irremediably lost. Here we show that this limitation can sometimes be lifted if the experimenter has the ability to probe physical processes in a coherent superposition of alternative configurations. As a concrete example, we consider the problem of phase estimation in the presence of a random phase kick, which in normal conditions is known to prevent the Heisenberg scaling. We provide a parallel protocol that achieves Heisenberg scaling with respect to the probes' energy, as well as a sequential protocol that achieves Heisenberg scaling with respect to the total probing time. In addition, we show that Heisenberg scaling can also be achieved for frequency estimation in the presence of continuous-time dephasing noise, by combining the superposition of paths with fast control operations.
