  The suppression of chaos in quantum reality is evident in quantum scars,
i.e., in enhanced probability densities along classical periodic orbits,
providing opportunities in controlling quantum transport in nanoscale quantum
systems. Here, we focus on the energy level statistics of perturbed
two-dimensional quantum systems exhibiting recently discovered, strong
perturbation-induced quantum scarring. In particular, we study the effect of
local perturbations and an external magnetic field on the eigenvalue statistics
and scarring. Energy spectra are analyzed to investigate the chaoticity of the
quantum system in the context of the Bohigas-Giannoni-Schmidt conjecture. We
demonstrate that perturbation-induced scarring is strong in classically fully
chaotic systems that, however, represent mixed eigenvalue statistics in the
quantum case.

Quantum Physics