Wen Xiao-Gang
Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Science. 2019 Feb 22;363(6429). doi: 10.1126/science.aal3099.
It has long been thought that all different phases of matter arise from symmetry breaking. Without symmetry breaking, there would be no pattern, and matter would be featureless. However, it is now clear that for quantum matter at zero temperature, even symmetric disordered liquids can have features, giving rise to topological phases of quantum matter. Some of the topological phases are highly entangled (that is, have topological order), whereas others are weakly entangled (that is, have symmetry-protected trivial order). This Review provides a brief summary of these zero-temperature states of matter and their emergent properties, as well as their importance in unifying some of the most basic concepts in nature.
长期以来，人们一直认为物质的所有不同相态都源于对称性破缺。没有对称性破缺，就不会有模式，物质将是无特征的。然而，现在很清楚的是，对于零温度下的量子物质，即使是对称无序液体也可以有特征，从而产生量子物质的拓扑相。一些拓扑相是高度纠缠的（即具有拓扑序），而另一些则是弱纠缠的（即具有对称性保护的平凡序）。本综述简要总结了这些零温度物质状态及其涌现性质，以及它们在统一自然界一些最基本概念方面的重要性。
