论文标题
Nagaoka-Hayashi的有效计算，用于多参数估计，可分开测量
Efficient computation of the Nagaoka--Hayashi bound for multi-parameter estimation with separable measurements
论文作者
论文摘要
在量子多参数计量学中找到最佳的可达到的精度是一个非微不足道的问题。解决此问题的一种方法涉及对界限的计算，该计算对我们可以估计某些物理量的准确程度施加了限制。这样的界限是固定在均方误差矩阵的轨迹上的孔cramer rao。当人们允许进行任何测量策略时，包括在探针的许多副本上进行集体测量时，孔隙结合是渐近可实现的结合。在这项工作中，我们引入了一个更严格的结合，用于在探针的有限拷贝上执行可分离测量时同时估算多个参数。这使其在实验可访问性方面更加相关。我们证明，可以通过将其作为半决赛程序来有效地计算该界限。我们用探针有限拷贝的几个集体测量示例说明了我们的界限。这些结果对饱和孔结合的必要要求有影响。
Finding the optimal attainable precisions in quantum multiparameter metrology is a non trivial problem. One approach to tackling this problem involves the computation of bounds which impose limits on how accurately we can estimate certain physical quantities. One such bound is the Holevo Cramer Rao bound on the trace of the mean squared error matrix. The Holevo bound is an asymptotically achievable bound when one allows for any measurement strategy, including collective measurements on many copies of the probe. In this work we introduce a tighter bound for estimating multiple parameters simultaneously when performing separable measurements on finite copies of the probe. This makes it more relevant in terms of experimental accessibility. We show that this bound can be efficiently computed by casting it as a semidefinite program. We illustrate our bound with several examples of collective measurements on finite copies of the probe. These results have implications for the necessary requirements to saturate the Holevo bound.
