[quantum-info] PIQuDos seminar Wed Nov 26: Dave Touchette

[Gus Gutoski]

Please join us on Wednesday, November 26 at 4pm in the Time room for a
quantum information seminar by Dave Touchette.

Title: Interactive Quantum Information Theory

Abstract:
In unidirectional communication theory, two of the most prominent
problems are those of compressing a source of information and of
transmitting data noiselessly over a noisy channel. In 1948, Shannon
introduced information theory as a tool to address both of these
problems. Since then, information theory has flourished into an
important field of its own. It has also been successfully extended to
the quantum setting, where it has also served to address questions
about quantum source compression and transmission of classical and
quantum data over noisy quantum channels.

However, in interactive communication theory, more specifically
communication complexity, it is much more recently that tools from
information theory have been successfully applied. Indeed, the
interactive nature of communication protocols in this setting imposes
new constraints and tools specific to this setting need to be
developed, both for the interactive analogue of source compression and
that of coding for noisy channels. The exciting field of classical
interactive information theory has been very active in recent years.
We discuss recent works for its quantum counterpart. In particular, we
discuss joint work showing that a constant factor overhead is
sufficient for robustly implementing interactive quantum communication
over noisy channels [1]. We also discuss work introducing a new notion
of quantum information complexity that exactly captures the amortized
cost per copy for implementing many copies of a communication task in
parallel, such that compressing to this information complexity leads
to a bounded-round direct sum theorem [2].
For both of these, we further discuss many interesting potential
research directions that follow.

[1] joint work with Gilles Brassard, Ashwin Nayak, Alain Tapp, Falk
Unger, QIP’14, FOCS’14
[2] Merge of arXiv:1404.3733 and arXiv:1409.4391, to appear at QIP’15