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Effects of scarring on quantum chaos in disordered quantum wells.

Research paper by Joonas Henrik JH Keski-Rahkonen, Perttu P Luukko, Sven S Åberg, Esa E Räsänen

Indexed on: 20 Dec '18Published on: 20 Dec '18Published in: Journal of physics. Condensed matter : an Institute of Physics journal



Abstract

The suppression of chaos in quantum reality is evident in quantum scars, i.e., in enhanced probability densities along classical periodic orbits. They provide opportunities in controlling quantum transport in nanoscale quantum systems. Here, we study energy level statistics of perturbed two-dimensional quantum systems exhibiting recently dis- covered, strong perturbation-induced quantum scarring. In particular, we focus on the effect of local perturbations and an external magnetic field on both 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 find that in systems where strong perturbation-induced scars are present, the eigenvalue statistics are mostly mixed, i.e., between Wigner-Dyson and Poisson pictures in random matrix theory. However, we report interesting sensitivity of both the eigenvalue statistics to the perturbation strength, and analyze the physical mechanisms behind this effect. © 2018 IOP Publishing Ltd.