BEGIN:VCALENDAR VERSION:2.0 PRODID:icalendar-ruby CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VTIMEZONE TZID:Europe/Vienna BEGIN:DAYLIGHT DTSTART:20260329T030000 TZOFFSETFROM:+0100 TZOFFSETTO:+0200 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3 TZNAME:CEST END:DAYLIGHT BEGIN:STANDARD DTSTART:20251026T020000 TZOFFSETFROM:+0200 TZOFFSETTO:+0100 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZNAME:CET END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20260415T110124Z UID:1772532000@ist.ac.at DTSTART:20260303T110000 DTEND:20260303T120000 DESCRIPTION:Speaker: Lincoln Carr\nhosted by Maksym Serbyn\nAbstract: Abstr act: One-dimensional Quantum cellular automata (QCA) in quantum circuits provide an experimentally realizable quantum computing testbed for quantum entangled dynamics\, spanning both integrable and quantum many-body chaot ic extremes.  In this work\, we establish a quantum many-body Kolmogorov- Arnold-Moser (KAM) framework in 1D QCA\, characterizing the breakdown of i ntegrability through a state-dependent hierarchy of conservation laws. Sta rting from the integrable limit of Goldilocks rules that map exactly onto free-fermion dynamics\, we introduce controlled\, locality-preserving pert urbations via symmetric Strang splitting. We investigate the breakdown of integrability by tracking the deformation of the first 13 local conserved charges directly within the native discrete-time circuit dynamics.Our cent ral finding in the circuit picture is the emergence of a stability hierarc hy of charges  determined by the algebraic structure of the perturbation generator\, classified into three distinct tiers: (i) robust invariants wh ich remain exactly conserved independent of perturbation strength\; (ii) r esonant actions which drift immediately at first order\; and (iii) KAM-lik e candidates\, in particular . We identify  as weakly non-resonant: it ex hibits anomalous super-delayed deformation under general initial condition s but remains conserved when initialized in an eigenstate of a specific Ab elian charge subset.Complementing this study of quantum circuits in discre te time\, we demonstrate rigorously that the associated continuous-time QC A Hamiltonian --- constructed via projector embeddings --- defines a funda mentally distinct dynamical system\, conserving only an Abelian subclass o f the 13 first charges from Goldilocks QCA.  Within this QCA-like Hamilto nian model\, we characterize the broader phenomenology of the integrabilit y-to-chaos crossover. We observe a universal transition from Poisson to Wi gner-Dyson spectral statistics and analyze the power-law growth of out-of- time-ordered correlators. Furthermore\, using Hamiltonian-based charge aut ocorrelators\, we map the stability of  to a regime of “confined chaos\ ,” where algebraic symmetries shield specific Hilbert space sectors from rapid thermalization\, providing a continuous-time counter-part of the KA M stability observed in the discrete circuit.References: Marc Andrew Valde z\, Daniel Jaschke\, David L. Vargas and Lincoln D. Carr\, “Quantifying Complexity in Quantum Phase Transitions via Mutual Information Complex Net works\,” Phys. Rev. Lett.\, v. 119\, p. 225301 (2017)Bhuvanesh Sundar\, Marc Andrew Valdez\, Lincoln D. Carr\, and Kaden R. A. Hazzard\, “A comp lex network description of thermal quantum states in the Ising spin chain\ ,” Phys. Rev. A\, v. 97\, p. 052320 (2018)Bhuvanesh Sundar\, Mattia Wals chaers\, Valentina Parigi\, and Lincoln D Carr\, “Response of quantum sp in networks to attacks\,” J. Phys. Complexity\, v.2\, p. 035008 (2021)LE Hillberry\, MT Jones\, DL Vargas\, P Rall\, N Yunger Halpern\, N Bao\, S Notarnicola\, S Montangero\, LD Carr\, “Entangled quantum cellular autom ata\, physical complexity\, and Goldilocks rules\,” Quantum Science and Technology\, v. 6\, p. 045017 (2021)EB Jones\, LE Hillberry\, MT Jones\, M Fasihi\, P Roushan\, Z Jiang\, A Ho\, C Neill\, E Ostby\, P Graf\, E Kapi t\, and LD Carr\, “Small-world complex network generation on a digital q uantum processor\,” Nature Communications v. 13\, p. 4483 (2022)Mattia W alschaers\, Nicholas Treps\, Bhuvanesh Sundar\, Lincoln D Carr\, and Valen tina Parigi\, “Emergent complex quantum networks in continuous-variables non-Gaussian states\,” Quantum Science and Technology\, v. 8\, p. 03500 9 (2023)LE Hillberry\, M Fasihi\, L Piroli\, N Yunger Halpern\, T Prosen\, and LD Carr\, “Classical simulability\, thermodynamics\, and integrabil ity of Goldilocks quantum cellular automata\,” Quantum Science and Techn ology\, under review\, arXiv:2404.02994 (2024)P Patnaik\, LE Hilberry\, T Prosen\, and LD Carr\, “Entanglement Dynamics of Integrable and Chaotic Quantum Cellular Automata: Towards a Quantum Many-body Kolmogorov-Arnold-M oser Theory\,” In preparation (2026)  LOCATION:Office Bldg West / Ground floor / Heinzel Seminar Room (I21.EG.101 )\, ISTA ORGANIZER:Stephanie.Dolot@ist.ac.at SUMMARY:Lincoln Carr: Entanglement Dynamics of Integrable and Chaotic Quant um Cellular Automata: Towards a Quantum Many-body Kolmogorov-Arnold-Moser Theory URL:https://talks-calendar.ista.ac.at/events/6131 END:VEVENT END:VCALENDAR