Recently, the quantum information study of quantum codes and quantum memory has led to the discovery of a new class of exactly solvable lattice models called the fracton models. The fracton models are similar to the better understood topological models in that they also support fractional excitations and have stable ground state degeneracy. But it is also clear that the fracton models exist beyond the realm of conventional topological order due to their extensive ground state degeneracy and the restricted motion of their fractional excitations. In this talk, we present a new framework, which we call the "foliated fracton order", to capture the nontrivial nature of the order in a large class of fracton models. Such a framework not only clarifies the connection between various different models, but also points to the direction of search for interesting new features.

Chen Xie obtained her B.A. in Physics from Tsinghua University in 2006 and PhD in Theoretical Physica from MIT in 2012. Subsequently, she received Miller Research Fellowships from Miller Institute for Basic Research in Science of UC Berkeley and worked as postdoctoral researcher there during 2012~2014. She then joined California Institute of Technology, and became Associate Professor of physics in 2017. Chen Xie's main research interests: novel phases and phase transitions in quantum condensed matter systems. Topics include: topological order in strongly correlated systems; dynamics in many-body systems; tensor network representation; quantum information application. She was awarded Sloan Research Fellowship and National Science Foundation Faculty Early Career Award in 2017.