Fracton phases are recent entrants to the roster of topological phases in three dimensions. They are characterized by subextensively divergent topological degeneracy and excitations that are constrained to move along lower dimensional subspaces, including the eponymous fractons that are immobile in isolation. We develop correlation function diagnostics to characterize Type I fracton phases which build on their exhibiting {\it partial deconfinement}. These are inspired by similar diagnostics from standard gauge theories and utilize a generalized gauging procedure that links fracton phases to classical Ising models with subsystem symmetries. En route, we explicitly construct the spacetime partition function for the plaquette Ising model which, under such gauging, maps into the X-cube fracton topological phase. We numerically verify our results for this model via Monte Carlo calculations.
Complementary views on electron spectra: From Fluctuation Diagnostics to real space correlations
我们研究了多体系统的微观性质与电子光谱之间的关系，实验上可以通过光电子能谱获得。在最近的一份文件[物理。114，236402（2015）]中，我们引入了“波动诊断”方法，以从电子自能中提取主导波矢量相关的玻色子波动。在这里，我们首先重新制定的理论方面的费米子模式，使其与共振价键（RVB）的波动更透明的连接。其次，通过使用大U展开，其中U是库仑相互作用，我们涉及到真正的空间相关的波动。因此，可以研究电子光谱如何与电荷，自旋，超导性和RVB类实空间相关性相关，拓宽了早期工作的分析[Phys. Rev. B 89，245130（2014）]。这种形式主义适用于赝隙物理的二维哈伯德模型，研究在动态集群近似。我们进行计算嵌入式集群与多达32个网站，有三个不等价的K-点在费米表面。我们发现，随着U的增加，关联函数逐渐达到与RVB状态一致的值。这首先发生在涉及到反节点的关联函数上，然后沿着费米面逐渐扩展到节点。同时，一个赝能隙沿着费米面打开。我们涉及到一个交叉从近藤样的状态到RVB样的本地集群状态和RVB和自旋波动的存在。这些变化是由一个强大的动量依赖于集群浴耦合沿费米表面。我们还展示了，从一个更算法的角度来看，如何在波动诊断耗时的计算可以大大简化。
Interplay between electronic correlation and metal-ligand delocalization in the spectroscopy of transition metal compounds: case study on a series of planar Cu$^{2+}$ complexes
