Speaker
Description
We study the nonstabilizerness, also named "quantum magic", in a variety of interacting quantum systems coupled with an environment. We first consider an infinite-range interacting spin-1/2 model, undergoing periodic kicking. In the thermodynamic limit, it is described by classical mean-field equations exhibiting regular and chaotic regimes. At finite size, the dynamics can be described through stochastic quantum trajectories. We find that the magic, averaged over trajectories, mirrors to some extent the classical chaotic behavior, while the entanglement entropy does not. Then we consider the Sachdev-Ye-Kitaev model, as well as nearest-neighbor XXZ-staggered spin chains. In the absence of measurements, the SYK model is the only one where the magic saturates the random-state bound and its scaling with the system size is well described by the theoretical prediction for quantum chaotic systems. In the presence of measurements, the magic always increases linearly with the size and displays no measurement-induced transitions in any of the considered models.
