Quantum Causal Graph Dynamics


Suppose that an entire graph evolves quantum mechanically and gets driven into superpositions of graphs of different connectivities and node populations. Suppose moreover that the evolution is causal, meaning that information can only propagate at a bounded speed, with respect to graph distance. We show that this quantum evolution must decompose into small, local unitary rewritings of graph disks. This unifies a result on Quantum Cellular Automata with another on Reversible Causal Graph Dynamics. To reach the result we formalize a notion of causality which is valid in the context of quantum superpositions of time-varying graphs, and has a number of good properties.

References: 1, 2, 3

Friday, February 11, 2022 15:00 Europe/Paris
GReTA seminar
Zoom registration: click here! Please consider joining the meeting already within the 15min prior to the start of the seminar to ensure your setup is functioning properly. You may connect with either the Zoom web or Zoom desktop clients.

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Pablo Arrighi
Pablo Arrighi

Pablo Arrighi studied at Imperial College, London, and defended his doctoral thesis at Cambridge University in 2003. He was appointed Maître de Conférences at the Université Grenoble-Alpes in 2005, Professor at Aix-Marseille Université in 2014, and finally Professor at the Université Paris-Saclay in 2020.

During his thesis, Pablo Arrighi described the first blind quantum computation protocol. He then pioneered the study of quantum programming languages. He next became one of the founders of the field of quantum cellular automata, i.e. discrete space discrete time quantum mechanics. His research also draws bridges between quantum networks and quantum gravity eg through the QISS consortium.