Mainz 2017 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 8: Quantum Information: Concepts and Methods II

Q 8.7: Vortrag

Montag, 6. März 2017, 18:30–18:45, P 2

Quantum Source-Channel Codes — •Fernando Pastawski, Henrik Wilming, and Jens Eisert — Freie Universität Berlin

Approximate quantum error-correcting codes are codes with "soft recovery guarantees" wherein information can be approximately recovered. In this article, we propose a complementary "soft code-spaces" wherein a weighted prior distribution is assumed over the possible logical input states. The performance for protecting information from noise is then evaluated in terms of entanglement fidelity. We apply a recent construction for approximate recovery maps, which come with a guaranteed lower-bounds on the decoding performance. These lower bound are straightforwardly obtained by evaluating entropies on marginals of the mixed state which represents the "soft code-space". As an example, we consider thermal states of the transverse field Ising model at criticality and provide numerical evidence that the entanglement fidelity admits non-trivial recoverability from local errors. This provides the first concrete interpretation of a bonafide conformal field theory as a quantum error-correcting code. We further suggest, that quantum source-channel codes could provide a framework to interpret the information structure of holography.