ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT wigner.mta.hu>]

*Wigner FK Quantum Optics and Quantum Information Seminar*
Efficient quantum transport in disordered interacting many-body networks

*Krzysztof Domino*
Institute of Theoretical and Applied Informatics,
Polish Academy of Sciences, Gliwice, Poland

Tuesday, 15 January 13:30, KFKI Campus, Bldg. 1, 1st floor, Conference Room

We discuss quantum stochastic walks, generalizations of both classical
walks and coherent (unitary) quantum walks. To model quantum stochastic
walks we use the Gorini–Kossakowski–Sudarshan–Lindblad equation. This
allows us to create a new model of the walk - the global stochastic walk.
We show the analysis of such a walk on the line, concerning the propagation
and time scaling of the second moment of the probability distribution of
the walk.
Concerning the propagation, we can observe additional amplitude
transitions, which change a graph topology. We call this spontaneous
moralization, since it changes the graph into "moral" one, where all parent
vertices that have a common child vertex are connected. We show by an
example, that this spontaneous moralization effect may have a meaningful
influence on the walk. Next we show how to correct the walk to prevent the
creation of such connections.
Concerning the scaling, we have ballistic propagation of the global
stochastic walk, for large propagation times. Numerics show that if such
walk is corrected, to prevent the change of graph topology, we have
super-diffusive propagation that may appear to be ballistic for
respectively large simulation time.

Based on:

K. Domino, A. Glos, M. Ostaszewski, Quant Inf & Comp 17, 973-986 (2017)
K. Domino et al, Quant Inf & Comp. 18, 181-197 (2018)

Everyone is welcome to attend.

János Asbóth