论文标题
量子多体系统中的模糊测量和粗粒
Fuzzy measurements and coarse graining in quantum many-body systems
论文作者
论文摘要
使用量子图形式主义，我们提供了一个框架，以构建多体系统的模糊和粗粒量子状态，以解释解决这些探测它们的真实测量设备的局限性。第一组地图处理粒子索引错误，而第二组则处理只能解决系统成分的一小部分的检测器的效果。我们将这些地图应用于旋转$ 1/2 $ xx链，从而获得了系统中纠缠产生和传播的模糊图。通过构造，这两个地图都是通过部分轨迹相关的，这使我们能够专注于前者的特性。我们完全表征模糊图，识别其对称性和不变空间。我们表明，在层状状态的粒子数量中以双重指数率降低，颗粒数量降低，对读取和使用多体量子系统信息的能力施加了严重的界限。
Using the quantum map formalism, we provide a framework to construct fuzzy and coarse grained quantum states of many-body systems that account for limitations in the resolution of real measurement devices probing them. The first set of maps handles particle-indexing errors, while the second deals with the effects of detectors that can only resolve a fraction of the system constituents. We apply these maps to a spin-$1/2$ XX-chain obtaining a blurred picture of the entanglement generation and propagation in the system. By construction, both maps are simply related via a partial trace, which allow us to concentrate on the properties of the former. We fully characterize the fuzzy map, identifying its symmetries and invariants spaces. We show that the volume of the tomographically accessible states decreases at a double exponential rate in the number of particles, imposing severe bounds to the ability to read and use information of a many-body quantum system.
