论文标题
在自旋链探针中的量子增强磁力测定法的顺序测量
Sequential measurements for quantum-enhanced magnetometry in spin chain probes
论文作者
论文摘要
给定资源相同的资源,量子传感器的估计精度优于他们的经典同行。到目前为止,通过利用叠加原理来实现量子增强的灵敏度。已经为特定形式的纠缠状态,自适应测量基础变化,关键的多体系统以及定期驱动系统的稳态获得了这种增强。在这里,我们引入了一种不同的方法,通过利用量子测量的性质及其随后的波功能崩溃,在多体探测中获得量子增强的灵敏度,而无需先前的纠缠。我们的协议包括一系列局部测量,没有重新定位,在多体探测过程中定期执行。随着序列数量的增加,感应精度被提高到超出标准极限之外,从而渐近地达到海森堡结合。协议的好处是多重的,因为它使用了产品初始状态并避免了复杂的初始化(例如先前的纠缠状态或关键的基态),并允许远程量子传感。
Quantum sensors outperform their classical counterparts in their estimation precision, given the same amount of resources. So far, quantum-enhanced sensitivity has been achieved by exploiting the superposition principle. This enhancement has been obtained for particular forms of entangled states, adaptive measurement basis change, critical many-body systems, and steady-state of periodically driven systems. Here, we introduce a different approach to obtain quantum-enhanced sensitivity in a many-body probe through utilizing the nature of quantum measurement and its subsequent wave-function collapse without demanding prior entanglement. Our protocol consists of a sequence of local measurements, without re-initialization, performed regularly during the evolution of a many-body probe. As the number of sequences increases, the sensing precision is enhanced beyond the standard limit, reaching the Heisenberg bound asymptotically. The benefits of the protocol are multi-fold as it uses a product initial state and avoids complex initialization (e.g. prior entangled states or critical ground states) and allows for remote quantum sensing.