Hi all,
Here is the abstract of tomorrow's talk.
Cheers,
Roger
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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.