HoloTube The Applied Holography Webinars Network

Speaker: Hugo Camargo

Affiliation:
Max Planck Institute for Gravitational Physics

Title:
Complexity of purification for free quantum fields

Abstract:
Finding pure states in an enlarged Hilbert space that encode a given quantum field theory mixed state as a partial trace is necessarily a challenging task.  Nevertheless, such purifications play the key role in characterizing quantum information theoretic properties of mixed states via quantities such as complexity of purifications. In this talk, we analyze this quantity in the case of a single interval, adjacent intervals and two symmetric intervals  in  the  vacuum  of  free  boson  and  Ising  conformal  field  theories  using,  for  the  first  time, the most general Gaussian purifications. We provide a comprehensive comparison with existing results and discuss what general properties of complexity of purification are appropriately captured by Gaussian purifications, and which are generically non-Gaussian.