论文标题
用量子多体疤痕增强的纠缠增强的计量
Entanglement enhanced metrology with quantum many-body scars
论文作者
论文摘要
尽管纠缠是量子增强计量学的关键资源，但并非所有纠缠都是有用的。例如，在多体热化的过程中，两分的纠缠迅速生长，自然饱和到体积定律中。这种类型的纠缠产生本质上是普遍存在的，但在大多数量子技术中都没有已知的应用。另一方面，对真正的多部分纠缠的一代，稳定和剥削对于计量应用来说是难以捉摸但非常理想的。最近已经显示，量子多体疤痕可能具有广泛的多部分纠缠。但是，到目前为止，该结构对真实应用程序的可访问性尚不清楚。在这项工作中，我们展示了如何使用包含量子多体疤痕的系统来动态生成稳定的多部分纠缠，并描述如何以超过标准量子限制的精确性来利用此结构进行相位估计。这样做的关键是对哈密顿量的身体动机的修改，该修改通过疤痕子空间中的动态产生了各种多部分纠缠状态。
Although entanglement is a key resource for quantum-enhanced metrology, not all entanglement is useful. For example in the process of many-body thermalisation, bipartite entanglement grows rapidly, naturally saturating to a volume law. This type of entanglement generation is ubiquitous in nature but has no known application in most quantum technologies. The generation, stabilisation and exploitation of genuine multipartite entanglement, on the other hand, is far more elusive yet highly desirable for metrological applications. Recently it has been shown that quantum many-body scars can have extensive multipartite entanglement. However the accessibility of this structure for real application has been so far unclear. In this work, we show how systems containing quantum many-body scars can be used to dynamically generate stable multipartite entanglement, and describe how to exploit this structure for phase estimation with a precision that beats the standard quantum limit. Key to this is a physically motivated modification of a Hamiltonian that generates a variety of multipartite entangled states through the dynamics in the scar subspace.
