Analysis Seminar

Sang-Gyun Youn, Seoul National University

"Information-theoretic analysis of covariant quantum channels"

It has a long history in quantum information theory to study quantum channels with symmetries, which we call covariant quantum channels. Some standard examples are the depolarizing quantum channels and Werner-Holevo quantum channels arising from the fundamental symmetries of the unitary group. There have been lots of studies for more general group symmetries, but with non-unified approaches and limitations to the fundamental group symmetries without the representation theory. This talk divides into two different topics. One part is to present a universal representation-theoretic framework to understand the structure of covariant quantum channels, and the other part is to discuss detailed information-theoretic properties of SU(2)-covariant quantum channels in some low-dimensional situations. More precisely, we present the complete characterization of their entanglement-breaking property, degradability, Holevo information, and (almost) super-activation of the coherent information.

MC 5417