Geometry of Process Matrices

          @misc{ scivideos_PIRSA:22060043,
            doi = {10.48660/22060043},
            url = {https://pirsa.org/22060043},
            author = {Ni Chuireain, Fionnuala},
            keywords = {Other Physics},
            language = {en},
            title = {Geometry of Process Matrices},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2022},
            month = {jun},
            note = {PIRSA:22060043 see, \url{https://scivideos.org/pirsa/22060043}}
          }
          

Abstract

Process matrices are objects that comprehensively describe multipartite quantum processes and their correlations. These matrices simultaneously play the roles of quantum states and quantum channels, and, to ensure a well-defined probability distribution, they are constrained to be positive. A key advantage of the process matrix formalism is that it can be used to describe processes with an indefinite causal order, which obey local quantum mechanics but cannot take place within a global causal structure. In this talk, i will give a complete introduction to the process matrix formalism and share preliminary results about the geometric positivity constraints of a special class of parameterised process matrices.