Open Problems

The Open Problems in Quantum Information page that was started by Reinhard Werner at TU Braunschweig and then moved to U Hannover (here the last recorded version (May 2022) in the Internet Archive) is now maintained here by a team at IQOQI Vienna.

Suggested further problems

We, the administrators of the Hannover open problem pages, will periodically check these contributions and move the ones we find most interesting to the main list.

Please leave your contact information so we can add it as in the list above.

Below is a very short sample problem with the main sections.

Maximal rate function for estimation


Show that there is no state estimation procedure whose large deviation rate function is equal to the relative entropy.


It is known from hypothesis testing that the relative entropy is an upper bound to the rate function.


  • M. Keyl, Quantum state estimation and large deviations,

Category:Resources for the QIP Community

Last modified: 

Friday, July 21, 2023 - 10:52