Debbie Leung: On the Power of PPT-preserving and Non-signalling Codes
0Debbie Leung (University of Waterloo)
On the Power of PPT-preserving and Non-signalling Codes
QuICS Workshop on the Frontiers of Quantum Information and Computer Science (September 29, 2015)
We will start by considering the general problem of transmitting quantum information over multiple uses of a memoryless quantum channel, which encompasses several rich but challenging areas of study including quantum error correcting codes, entanglement purification, and quantum channel capacity.
We will then discuss recent development in optimal finite block-length communication, a refinement to the study of quantum channel capacity. To approach this difficult problem we consider a relaxation of the optimization that corresponds to channel codes assisted by operations that are non-signalling between the sender and the receiver, and that are PPT-preserving (cannot create entanglement). The optimal rate-distortion tradeoff can be formulated as a semidefinite program and can be precisely computed. We will discuss several applications of our results.
This is joint work with William Matthews of the University of Cambridge.