Large-N-approximated field theory for multipartite entanglement
Seminar author:Giuseppe Florio
Event date and time:05/31/2016 02:30:pm
Event location:GIQ Seminar room
Event contact:
We will study the properties of multipartite entanglement by adopting the concepts and tools of classical statistical mechanics. In order to explore the rich landscape that ensues, we shall make use of techniques that are based on the analysis of diagrams that naturally arise when one considers a high-temperature expansion of the distribution function of the measure of multipartite entanglement (the potential of multipartite entanglement). Unfortunately, the evaluation of the contributions of different kinds of graphs and their resummation is not a simple task. One would like to find a strategy to select and sum a family of diagrams which dominate the result in one particular limit.
We replace the (complex) coefficients of the wave function with Nc-dimensional real vectors.
This generalization appears in a natural way by analyzing the mathematical structure of the measure used to characterize the multipartite entanglement. Clearly, the physics of the case Nc much larger than 2 will not be the same as in the original problem Nc =2, however, as it is often the case with large-Nc expansions, the two problems share some important ingredients and salient features
The symptoms of a phase transition are present for multipartite entanglement in the limit of large Nc. Moreover, we will see an explicit example where the frustration of multipartite entanglement disappears if the value of Nc is large enough.
P. Facchi et al. Phys. Rev. A, 92, 062330 (2015).