Many-body Entanglement: From Topological Order to Quantum Computation

          @misc{ pirsa_PIRSA:11110140,
            doi = {10.48660/11110140},
            url = {https://pirsa.org/11110140},
            author = {Chen, Xie},
            keywords = {Condensed Matter},
            language = {en},
            title = {Many-body Entanglement: From Topological Order to Quantum Computation},
            publisher = {Perimeter Institute},
            year = {2011},
            month = {nov},
            note = {PIRSA:11110140 see, \url{https://pirsa.org}}
          }
          

Abstract

Many-body entanglement, the special quantum correlation that exists among a large number of quantum particles, underlies interesting topics in both condensed matter and quantum information theory. On the one hand, many-body entanglement is essential for the existence of topological order in condensed matter systems and understanding many-body entanglement provides a promising approach to understand in general what topological orders exist. On the other hand, many-body entanglement is responsible for the power of quantum computation and finding it in experimentally stable systems is the key to building large scale quantum computers. In this talk, I am going to discuss how our understanding of possible many-body entanglement patterns in real physical systems contributes to the development on both topics. In particular, I am going to show that based on simple many-body entanglement patterns, we are able to (1) completely classify topological orders in one-dimensional gapped systems, (2) systematically construct new topological phases in two and higher dimensional systems, and also (3) find an experimentally more stable scheme for measurement-based quantum computation. The perspective from many-body entanglement not only leads to new results in both condensed matter and quantum information theory, but also establishes tight connection between the two fields and gives rise to exciting new ideas.