[quantum-info] PIQuDos this week

[Roger Colbeck]

Hi all,

This Wednesday we have Eric Chitambar speaking at 4pm in the time room. 
  His title and abstract are below.

Best wishes,

Roger

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Title: More Rounds of Measurement Increase the Abilities to Locally 
Transform Quantum States

Abstract: The class of Local Operations with Classical Communication 
(LOCC) is a fundamental object in quantum communication and entanglement 
theory. However, despite its importance, LOCC still lacks a clear 
understanding from both a physics and math perspective. For instance, it 
is unknown the extent to which more rounds of measurement and 
communication can enhance the ability to perform certain tasks.

In this talk, we will consider the problem of random-pair EPR 
distillation in which three qubit entanglement is converted into 
bipartite maximal entanglement with the target pair a priori 
unspecified.  I will show that for certain random-pair distillations, 
there exists tight lower bounds on the number of LOCC rounds needed to 
achieve a given overall success probability.  Furthermore, I will 
describe certain entanglement transformations that are possible if and 
only if the protocol uses an infinite (unbounded) number of rounds. 
Interestingly, the number of rounds required to distil bipartite 
entanglement from particular multipartite states can depend 
discontinuously on the amount of entanglement distilled.