Wydarzenia

Temat: Quantum circuit complexity for linearly polarised light
Prowadzący: Jean-Pierre Gazeau, Université Paris Cité

I present a form of quantum circuit complexity that extends to open systems. To illustrate the methodology, I focus on a basic model where the projective Hilbert space of states is depicted by the set of orientations in the Euclidean plane. Specifically, I investigate the dynamics of mixed quantum states as they undergo interactions with a sequence of gates. This approach involves the analysis of sequences of real 2X2 density matrices. Such a mathematical model is physically exemplified by the Stokes density matrices, which delineate the linear polarisation of a quasi-monochromatic light beam, and the gates, which are viewed as quantum polarisers, whose states are also real 2X2 density matrices. The interaction between polariser-linearly polarised light is construed à la Von Neumann within the context of this quantum formalism. Each density matrix for the light evolves in a way analogous to a Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) process during the time interval between consecutive gates. Notably, when considering an upper limit for accuracy, it is shown that the optimal number of gates follows a power-law relationship. From a submitted article co-authored by E. Curado A. Maioli, D. Noguera (CBPF, Rio), S. Faci (UFF, Rio), T. Koide (UFRJ, Rio).