标题： 无序磁体中量子纠缠的普遍形状依赖性 显示英文标题

标题： Universal shape-dependence of quantum entanglement in disordered magnets

摘要： 无序量子磁体不仅在实验上相关，而且提供了高效的计算方法来计算低能态以及各种量子关联度量。 在这里，我们使用一种高效实现的渐近精确强无序重正化群方法，对二维典型随机横场伊辛模型中的量子纠缠进行了系统分析。 相图已知由三个不同的无限无序固定点（IDFPs）控制，我们在此研究了这些固定点。 对于正方形子系统，最近已经确定，在所有三个IDFPs下，由于子系统的角部，量子纠缠具有普遍的对数修正。 这种角部贡献已被提出作为“纠缠灵敏度”，一个用于定位相变和测量关联长度临界指数的有用工具。 为了更深入的理解，我们量化了角部贡献如何依赖于子系统的形状。 虽然角部贡献保持普遍性，但每个普适类中的形状依赖性在定性上有所不同，这也通过线段子系统（骨架纠缠的一个特例）得到了确认。 因此，与共形不变系统不同，一般来说，不同的子系统形状是揭示无序量子系统中相变新普适信息的多功能探针。 显示英文摘要

摘要： Disordered quantum magnets are not only experimentally relevant, but offer efficient computational methodologies to calculate the low energy states as well as various measures of quantum correlations. Here, we present a systematic analysis of quantum entanglement in the paradigmatic random transverse-field Ising model in two dimensions, using an efficient implementation of the asymptotically exact strong disorder renormalization group method. The phase diagram is known to be governed by three distinct infinitely disordered fixed points (IDFPs) that we study here. For square subsystems, it has been recently established that quantum entanglement has a universal logarithmic correction due to the corners of the subsystem at all three IDFPs. This corner contribution has been proposed as an "entanglement susceptibility", a useful tool to locate the phase transition and to measure the correlation length critical exponent. Towards a deeper understanding, we quantify how the corner contribution depends on the shape of the subsystem. While the corner contribution remains universal, the shape-dependence is qualitatively different in each universality class, also confirmed by line segment subsystems, a special case of skeletal entanglement. Therefore, unlike in conformally invariant systems, in general different subsystem shapes are versatile probes to unveil new universal information on the phase transitions in disordered quantum systems.