Entanglement entropy and infinite randomness fixed points in disordered magnetic and non-abelian quasi-particle chains

          @misc{ pirsa_PIRSA:10050071,
            doi = {10.48660/10050071},
            url = {https://pirsa.org/10050071},
            author = {Refael, Gil},
            keywords = {},
            language = {en},
            title = {Entanglement entropy and infinite randomness fixed points in disordered magnetic and non-abelian quasi-particle chains},
            publisher = {Perimeter Institute},
            year = {2010},
            month = {may},
            note = {PIRSA:10050071 see, \url{https://pirsa.org}}
          }
          

Abstract

Many one dimensional random quantum systems exhibit infinite randomness phases, such as the random singlet phase of the spin-1/2 Heisenberg model. These phases are typically the result of destabilizing systems described by a conformal field theory with disorder. Interestingly, entanglement entropy in 1d infinite randomness phases also exhibits a universal log scaling with length. In my talk I will touch upon calculating the entanglement entropy for inifinite-randomness phases, as well as describe the exotic infinite randomness phases realized in chains of non-abelian anyon chains. It was speculated that the entanglement entropy of an infinite-randomness phase is associated with the direction of RG flow, just as the c-theorem dictates the direction of RG flows for CFT's. I will also show that the entanglement entropy in disordered non-abelian chains provide the only known counter example.