Almost regular weekly seminar.

[PHOTO] 17/02 11:00
Piotr Frackiewicz (Slupsk)
Strong isomorphism in quantum games
I would recall basic facts about game theory and the Eisert-Wilkens-Lewenstein scheme for quantum game. Next, I would talk about the role of strong isomorphism between games in quantum games.
[PHOTO] ??/?? 13:00
Maurice de Gosson (Vienna)
For which values of Planck's constant is a Gaussian the Wigner distribution of a pure or mixed state
We begin by briefly discussing the notion of positivity for trace class operators, and thereafter consider in detail the case of trace class operators associated with a Gaussian; the Gaussian case is, in fact, the only one which is fully understood mathematically. We finally make some conjectures bout the general case (work in progress).
[PHOTO] ??/?? 11:00
Martin Schwarz (Berlin, Germany)
Approximating local observables on projected entangled-pair states
​Tensor network states are for good reasons believed to capture ground states of gapped local Hamiltonians well arising in the condensed matter context, states which are in turn expected to satisfy an entanglement area law. However, the computational hardness of contracting projected entangled pair states in two and higher dimensional systems is often seen as a significant obstacle when devising higher-dimensional variants of the density-matrix renormalisation group method. In this work, we show that for those projected entangled pair states that are expected to provide good approximations of such ground states of local Hamiltonians – in a sense made precise in readings of the so-called PEPS conjecture – one can compute local expectation values in quasi-polynomial time. We therefore provide a complexity-theoretic justification of why state-of-the-art numerical tools work so well in practice. We comment on how the transfer operators of such projected entangled pair states have a gap. We finally turn to the computation of local expectation values on quantum computers, contributing to the discussion why this would be a meaningful application for a small-scale quantum computer.
Place: RCQI, Institute of Physics, Dúbravská cesta 9, Bratislava | map |

Specialized lecture courses. Currently no lectures are scheduled.

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Joint quantum scientific gathering of groups from Wien, Brno and Bratislava.

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See previous seminars | here |
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