>VITAE:
19871996: Study in Physics at the University
of Hamburg (Germany), Diploma and PhD in the field of "algebraic
quantum field theory" at the II. Institute for Theoretical Physics
in the group of Klaus Fredenhagen.
19971999: Research project in quantum field
theory an euclidean field theory at the Erwin Schrödinger International
Institute for Mathematical Physics (ESI), Vienna associated with the group
of Jakob Yngvason at the Institut für Theoretische Physik, University
Vienna. Funding by the DFG, the ESI and the Jubiläumsfonds der Oesterreichischen
Nationalbank.
Since 2000: Research associate at the Institut
für Mathematische Physik, Technical University Braunschweig, in the
quantum information theory research group of Reinhard Werner. Funding
by the DFG and EQUIP.



Stinespring's dilation theorem is the basic structure theorem
for quantum channels: it states that any quantum channel arises from a unitary
evolution on a larger system. Here we prove a continuity theorem for Stinespring's
dilation: if two quantum channels are close in cbnorm, then it is always
possible to find unitary implementations which are close in operator norm,
with dimensionindependent bounds.
This result generalizes Uhlmann's theorem from states to channels and allows
to derive a formulation of the informationdisturbance tradeoff in terms
of quantum channels, as well as a continuity estimate for the nobroadcasting
theorem. We briefly discuss further implications for quantum cryptography,
thermalization processes, and the black hole information loss puzzle. 