266th RQC Seminar

• 講演者

  Mr. Filippo Ferrari
  ( The Swiss Federal Institute of Technology in Lausanne (EPFL) )

• 日程

  2026年4月20日(月), 16:00 - 17:00(4:00 p.m.-5:00 p.m.)

• 開催場所

  ハイブリッド（Zoom,
  345-347 Seminar Room, 3F, Main Research Building, Wako Campus / 和光地区 研究本館3階 セミナー室 (345-347) (C01))

• 講演タイトル

  Dissipative quantum chaos in quantum technologies: from theory to hardware platforms

• お問合せ

  norilab_rqc_assist[at]ml.riken.jp

講演概要
The study of chaos and integrability in open quantum many-body systems is central inmany research areas, from high-energy physics to quantum optics, from quantum technologies to condensed matter. Understanding chaotic behavior in quantum platforms is crucial for quantum simulation and computation: analog and digital quantum simulators can exploit controllable chaos while being vulnerable to uncontrollable chaotic dynamics in their basic components.
Essentially, any quantum technology platform can be modeled as an open quantum manybody system. To date, chaos in open quantum systems is understood through non-Hermitian random matrix theory: the Liouvillian superoperator governing dissipative dynamics behaves as a large random matrix in chaotic regimes [1, 2]. Recent advances connecting dissipative chaos with the dynamics of single stochastic quantum trajectories provided new tools to explain previously elusive phenomena [3].
Equipped with these state-of-the-art theoretical methods, we explore the emergence of quantum chaos in several quantum hardware platforms. First, we consider superconducting circuits [4]. A leading paradigm in superconducting qubits is that of bosonic cat qubits, due to their intrinsic error correction schemes [5]. We demonstrate how dissipative quantum chaos qualitatively modifies the cat qubit properties and hinders coherent quantum information manipulation, clarifying the necessary ingredients for chaotic behavior in both fully quantum and semiclassical frameworks [6]. Second, we consider quantum optomechanics [7]. Due to the very low loss rates, optomechanical systems are serious candidates for hosting useful and long-lived quantum states. We investigate a parametrically-driven optomechanical setup that exhibits symmetry-breaking phase transitions. We uncover emergent dissipative chaos originating from the nonlinear coupling and reveal how expected phase transitions lead to complex chaotic behavior spanning quantum to classical regimes [8]. Third, we consider ultracold fermionic atoms in optical cavities [9]. Thanks to the long-range interactions mediated by the cavity and an engineered controllable disorder, this setup offers the possibility of simulating in the laboratory random all-to-all fermionic systems such as the celebrated Sachdev-Ye-Kitaev model, with profound implications in condensed matter and holography [10]. We investigate how cavity and atomic dissipation affect unitary many-body quantum chaos and identify experimentally accessible fingerprints [11].
Our work establishes how quantum technology platforms naturally exhibit dissipative quantum chaos due to their inherent complexity, paving the way for its experimental characterization and control.

[1] G. Akemann, M. Kieburg, A. Mielke, and T. Prosen, Phys. Rev. Lett. 123, 254101 (2019).
[2] L. S´a, P. Ribeiro, and T. Prosen, Phys. Rev. X 10, 021019 (2020).
[3] F. Ferrari, L. Gravina, D. Eeltink, P. Scarlino, V. Savona, and F. Minganti, Phys. Rev. Res. 7, 013276 (2025).
[4] A. Blais, A. L. Grimsmo, S. Girvin, and A. Wallraff, Rev. Mod. Phys. 93, 025005 (2021).
[5] M. Mirrahimi, Z. Leghtas, V. V. Albert, S. Touzard, R. J. Schoelkopf, L. Jiang, and M. H. Devoret, New J. Phys. 16, 045014 (2014).
[6] F. Ferrari, J. Cohen, V. Savona, and F. Minganti, To appear (2026).
[7] M. Aspelmeyer, T. J. Kippenberg, and F. Marquardt, Rev. Mod. Phys. 86, 1391 (2014).
[8] G. Bragadin, A. Mercurio, F. Ferrari, L. Fioroni, V. Macr`ı, and V. Savona, To appear (2026).
[9] F. Mivehvar, F. Piazza, T. Donner, and H. Ritsch, Adv. Phys. 70, 1 (2021).
[10] R. Baumgartner, P. Pelliconi, S. Bandyopadhyay, F. Orsi, N. Sauerwein, P. Hauke, J.-P. Brantut, and J. Sonner, (2024), arXiv:2411.17802 [quant-ph].
[11] F. Ferrari, F. Orsi, E. Fedotova, O. Rios Alves, J.-P. Brantut, and V. Savona, To appear (2026).