Hi all,
Tomorrow we switch to the new time of the QIT seminar, 2pm. The zoom link remains the same, https://ethz.zoom.us/j/362994444.
Alberto Rolandi will present his master thesis, supervised by Henrik, entitled "Extensivity of Rényi Entropies in Many-Body Systems". Here is the abstract:
We prove the approximate sub-additivity of min-entropies in Gibbs states above a universal threshold temperature up to boundary terms. Under the further assumption of extensive free energy, we establish that there exist subsystems with extensive Rényi entropies. Second, we study the Rényi entanglement entropies for disconnected subsystems in spin-chains described by generic (gapped), translational invariant matrix product states. We provide an explicit lower-bound to the Rényi entropy densities of the subsystem consisting of every k-th spin in the thermodynamic limit. As a side-result, we obtain a lower bound for the expansion coefficient of a unital primitive quantum channel in terms of its Kraus-rank.
Best,
-joe