SKM 2023 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DY: Fachverband Dynamik und Statistische Physik

DY 48: Dynamics and Chaos in Many-Body Systems I (joint session DY/TT)

DY 48.3: Vortrag

Donnerstag, 30. März 2023, 15:30–15:45, MOL 213

Signatures of the interplay between chaos and local criticality on the dynamics of scrambling in many-body systems — Felix Meier¹, •Mathias Steinhuber², Juan Diego Urbina², Daniel Waltner¹, and Thomas Guhr¹ — ¹University of Duisburg-Essen, Lotharstr. 1, 47048 Duisburg, Germany — ²University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany

Fast scrambling, quantified by the exponential initial growth of Out-of-Time-Ordered-Correlators (OTOCs), is the ability to efficiently spread quantum correlations among the degrees of freedom of interacting systems, and constitutes a characteristic signature of local unstable dynamics. As such, it may equally manifest both in systems displaying chaos or even in integrable systems around criticality. We discuss the results from our recent publication [1], where we go beyond these two well-studied regimes with an exhaustive study of the interplay between local criticality and chaos. We address many-body systems with a well-defined classical (mean-field) limit, as coupled large spins and Bose-Hubbard chains, thus allowing for semiclassical analysis. Our aim is to investigate the dependence of the exponential growth of the OTOCs, defining the quantum Lyapunov exponent λ_q on quantities derived from the classical system with mixed phase space, specifically the local stability exponent of a fixed point λ_loc as well as the maximal Lyapunov exponent λ_L of the chaotic region around it.
[1] Meier, F., Steinhuber, M., Urbina, J. D., Waltner, D. & Guhr, T. arxiv:2211.12147