Hi all, Here is the abstract of tomorrow's talk. Cheers, Roger
------- Title: Quantum Information as Complementary Classical Information: Secret Key and Entanglement Distillation via Processing Complementary Classical Information
Abstract: Since the breakthrough by Calderbank, Shor, and Steane on the existence of quantum error-correcting codes, an oft-used notion in quantum information theory is that we can treat quantum information essentially as a strange combination of two types of classical information, pertaining to two complementary observables "amplitude" and "phase". Correcting errors afflicting either of these observables is sufficient to restore the quantum information to its original state. This approach is also appealing on a more fundamental level, as it suggests that the important differences between classical and quantum information processing originate from the phenomenon of complementarity, which is at the heart of the difference between classical and quantum mechanics. However, the central results of quantum information theory established recently, such as the achievable rate of quantum communication over a noisy channel, follow a different approach termed decoupling which has a natural origin in the study of quantum cryptography. We show that the decoupling-based results can be concretely established in the complementary classical information picture. By adopting an information-theoretic approach to complementarity, we are able to construct entanglement distillation protocols which straightforwardly seek to distill amplitude and phase correlations without venturing into decoupling. This gives new and intuitive proofs of both the noisy channel coding theorem and the asymptotic rates of both secret-key distillation and state merging.
This is joint work with J.-C. Boileau.