BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT SUMMARY:[Workshop] Dynamics and control of classical and quantum systems DTSTART:20260602T120000Z DTEND:20260605T130000Z DTSTAMP:20260518T202722Z CATEGORIES: DESCRIPTION:From Tuesday\, June 2 to Friday\, June 5\, 2026\, Mines Paris – PSL will host an international workshop to mark the end of the ERC Q-F eedback project.\n \nQuantum technologies\, such as quantum computers and simulators\, have the potential to revolutionize our computing speed\, co mmunications security\, and measurement accuracy. The power of quantum tec hnology relies on two key but fragile resources: quantum coherence and ent anglement. This promising field faces a major question: how can we design machines that exploit quantum properties on a large scale and effectively protect them from external disturbances (decoherence)\, which tend to elim inate the quantum advantage?\nMaking a system robust and stable in the fac e of external disturbances is one of the fundamental problems in control s ystem theory. This workshop brings together experimentalists in quantum ph ysics and technologies\, and researchers in control theory. The aim is to study the role of control engineering in emerging quantum technologies. Th is workshop is supported by ERC Q-feedback.\n \nSchedule\n \nYou can fin d the event schedule here \nTuesday\, June 2\n14:00-14:45 Registration\n 14:45-15:00 Introduction\n15:00-16:00 Michel Brune (Laboratoire Kastler Brossel\, CNRS\, Collège de France) – Trapped Circular Rydberg Atoms fo r Quantum Simulation: Quantum Non-Demolition Detection and Optical Manipul ations.\nNeutral atoms trapped in optical tweezers and promoted to Rydberg states are one of the most promising platforms for quantum simulation. Du e to their exceptional lifetime\, circular Rydberg atoms additionally offe r an unprecedented potential for being trapped over timescales of tenth of milliseconds at the temperature of 4K as compared to the 100 µs lifetime of the low angular momentum Rydberg levels involved in present neutral-at om-based quantum simulators. We will present a state-selective and non-des tructive detection method for single trapped circular atoms of Rubidium in optical tweezer. The method is based on a “dual-Rydberg” architecture combining arrays of circular atoms as computational qubits and of low ang ular momentum ancilla Rydberg atom for readout. The scheme also allows for optically addressing individual circular atoms. We will also present anot her circular-atom-based quantum simulator using strontium atoms with the a dvantage of potential optical manipulation of the second valence electron once the first one is promoted to a circular state.\n16:00-16:30 Coffee br eak\n16:30 – 17:30 Nicolas Petit (Mines Paris – PSL\, Centre Automatiq ue et Systèmes) – Real-time estimation of kinematic variables for advan ced mechanical systems\nThis presentation will highlight innovative uses o f miniature sensors for estimating kinematic variables. The work presented applies to both rigid and flexible bodies\, and is implemented in closed- loop control for several autonomous or semi-autonomous systems in robotics \, urban mobility\, and aerodynamics.\nThe talk will specifically address fundamental questions regarding the synthesis of asymptotic observers for reconstructing the attitudes of multi-articulated bodies\, as well as velo city estimation for high-speed symmetric aerodynamic bodies.\n17:30 – 18 :30 Mazyar Mirrahimi (Inria\, Quantic Team) – Biased-noise qubits for fault-tolerant quantum computation\nThe theory of quantum error correction and fault-tolerant computation provides a route towards handling the nois e in quantum processors but comes at the expense of  significantly  incr eased complexity in their physical implementation. One promising approach towards such hardware-efficient fault-tolerant processors is to take advan tage of the noise bias that is either naturally present in some physical p latforms or is engineered through a built-in protection against one type o f noise. After an introduction to such biased-noise qubits\, I will review various approaches to operate them and benefit from this noise-bias to re duce the complexity of error correction. \n19:00-21:00 Welcome cocktail\ n \nWednesday\, June 3\n9:00-10:00 Philippe Campagne-Ibarcq (Inria\, Qua ntic Team) – Challenges and progress toward dynamical stabilization of a dvanced bosonic qubits\nOver the past decade\, dynamical stabilization of bosonic qubits has emerged as a promising approach for hardware-efficient protection of quantum information. However\, applying these techniques to more complex encodings than the Schrodinger cat code requires exquisite co ntrol of high-order wave mixing processes in order to enable specific mult iphotonic dissipation channels while avoiding unintended non-linear intera ctions.In this talk I will present how methods originally designed for two -component cat qubits can be extended to stabilize multi-component cat sta tes and GKP states. I will then detail pitfalls and recent progress toward the experimental implementation of these ideas.\n10:00-10:30 Coffee brea k\n10:30-11:30  John Gough (Aberystwyth University) – Quantum Feedback Networks: Markovian and Non-Markovian Features\nWe review the theory of qu antum feedback networks and show how it gives a framework for a system the oretic description applicable to quantum engineering. The network rules ar e presented along with an overview of feedback based control. We will also discuss recent advances in modelling non-Markovian behaviour (joint work with N. Amini\, H. Ding\, and G. Zhang).\n11:30-12:30 Audrey Bienfait (É cole Normale Supérieure de Lyon\, CNRS) – Electronic spins for quantum memories\nAmong platforms for storing quantum states in the microwave doma in\, solid state spin ensembles addressed via superconducting circuits sta nd out for their multimodal storage capability and the second-long coheren ce time when operated at clock transitions.Successful implementation of a practical memory scheme requires several keys features\, such as the abili ty to tune on-demand the frequency and the bandwidth of the resonator. In this talk\, we will present a superconducting circuit architecture accompl ishing both\, allowing strong coupling to an ensemble of bismuth dopants i n silicon. We also explore strategies for reaching the near unity cooperat ivity regime that is key for high-storage efficiency.\n12:30-14:00 Lunch\ n14:00-15:00 Karine Beauchard  (École Normale Supérieure de Rennes) – Small time control of the bilinear Schrödinger equation.\nWe consider Sc hrödinger PDEs\, posed on a boundaryless Riemannian manifold M\, with b ilinear control. We propose a new method to prove the global approximate controllability. Contrarily to previous ones\, it works in arbitrarily sma ll time and does not require a discrete spectrum. This approach consists i n controlling separately the radial part and the angular part of the wavef unction thanks to the control of the group of diffeomorphisms of M and t he control of phases. Surprisingly\, the control of phase implies the con trol of diffeomorphisms. The proofs rely on Lie bracket techniques. We dev elop this approach on two examples of Schrödinger equations\, posed on t he d-dimensional torus or Euclidian space.\n15:00-16:00  Zaki Leghtas (M ines Paris PSL\, Quantic Team) – Encoding Quantum information in Dynamic al Superconducting Circuits\nSuperconducting circuits are macroscopic arra ngements of pieces of superconducting material\, assembled in the form of metallic wires and plates. Their state is described by collective degrees of freedom such as voltages and currents\, that behave quantum mechanicall y. On the other hand\, the area of mathematics known as “dynamical syste ms”\, studies the time evolution and stability of driven systems. In thi s talk\, I will show how we encode quantum information in driven supercond ucting circuits\, and the benefits of this technique for the emergence of quantum technologies.\n16:00-16:30 Coffee break\n16:30-17:30 Bernhard Masc hke (Université Claude Bernard Lyon 1) – Port-Hamiltonian formulations of open quantum systems\nPort-Hamiltonian systems are a formulation the dy namics of open physical systems using an extension of Hamiltonian systems obtained by augmenting the state space with pairs of conjugated external v ariables\, called port-variables and defining its dynamics with respect to a Dirac structure extending their Poisson bracket. It has been instrument al for the derivation of energy-aware nonlinear control of multi-physical systems. In this talk\, we shall present some preliminary work on their ap plication to open quantum systems. We shall first consider quantum circuit s and show how their dynamics may be formulated on Poisson structure and D irac structure derived from the topology of the circuits and how port-vari ables may be introduced. Second\, we shall present a recent extension of p ort-Hamiltonian systems to dissipative systems which are defined with resp ect to a 4-contravariant bracket which  extends Poisson bracket in such a way to encompass the entropy balance. And we shall investigate how this m ay be applied to the Lindblad equations and relate it to their metriplecti c formulation.\n \nThursday\, June 4th\n9:00-10:00 Patrice Bertet (CEA ir amis) – Quantum control of individual spins in solids\nSpins in solids a re interesting qubit candidates for quantum technologies\, owing to their long coherence times. These applications require novel methods to detect a nd address them coherently. I will describe methods developed recently in our laboratory to measure and control individual electron and nuclear spin s in solids at 10mK. Individual electron spins are coupled to a supercondu cting microwave resonator to enhance their radiative relaxation. The spont aneously emitted microwave photons are detected by a microwave photon coun ter based on a superconducting transmon qubit. Individual nuclear spins ar e readout and driven via their hyperfine coupling to the electron spin.\n1 0:00-10:30 Coffee break\n10:30-11:30 Michel H. Devoret (Google Quantum A I\, University of California\, Santa Barbara) – Introduction to quantum superconducting circuits control questions\nForty years ago\, a fundamenta l inquiry into the possible quantum-ness of macroscopic variables—curren ts and voltages—launched the field of quantum superconducting circuits. The foundational experiments at Berkeley that first uncovered macroscopic quantum tunneling and energy quantization led progressively to the current era of “artificial atoms.” Unlike natural atoms\, these engineered sy stems allow the tailoring of energy levels and matrix elements by adjustme nts of dimensional fabrication parameters. The ground and first excited st ates of these circuits are now utilized as qubits in processors exceeding 100 qubits\, capable of executing quantum algorithms that challenge classi cal computation. Adaptative calibration and error correction of large-scal e quantum superconducting circuits pose pressing questions to the theory o f quantum control.\n11:30-12:30 Christiane Koch (Freie Universität Berlin ) – Quantum control and engineering with two-body interactions\nQuantum control protocols often rely on multi-body interactions that must be engin eered through sequences of two-body couplings. This overhead can lead to s ignificant hardware complexity or\, in the worst case\, undermine a protoc ol’s viability. In this talk\, I will illustrate these challenges using examples from dissipative state preparation [1\,2] and parity measurements in continuous quantum error correction [3]. Conversely\, physical qubits are typically embedded in multi-level systems\, and  recent developments have begun to leverage these larger structures as a resource\, notably in the construction of erasure qubits and bosonic codes. Taken together\, the se observations suggest a need to rethink what constitutes a “free” ph ysical resource versus an “added” cost\, thereby redefining the optimi zation problem of implementing practical quantum computing.\n[1] Langbehn et al. PRX Quantum 5\, 030301 (2024)\n[2] Langbehn\, Mouloudakis et al. ar Xiv:2506.11964\n[3] Halaski & Koch\, arXiv:2603.02106\n12:30-14:00 Lunch\n 14:00-15:00 Madalin Guta (University of Nottingham) – Optimal estimatio n of quantum Markov chains using coherent output post processing and displ aced-null measurements\nIn this presentation I will discuss the problem of estimating dynamical parameters of a quantum Markov chain\, in particular how to achieve the quantum Cramer-Rao bound using sequential measurements and computationally efficient estimators. The key tool will be the use of a coherent quantum absorber which transforms the problem into a simpler o ne pertaining to a system with a pure stationary state at a reference para meter value. Motivated by the proposal in [1] I will consider counting out put measurements and show how the statistics of the counts can be used to compute a simple\, asymptotically optimal estimator of the unknown paramet er. For this\, I will introduce translationally invariant modes (TIMs) of the output and show that these modes are Gaussian in the limit of large ti mes and capture the entire quantum Fisher information of the output. Moreo ver\, the counting measurement provides an effective joint measurement of the TIMs number operators. The unknown parameter is estimated using a two stage estimation procedure. A rough estimator is first computed using a si mple measurement\, and is used to set the absorber parameter. Due to non-i dentifiability issues of the counting measurement the reference parameter needs to be shifted away from the initial rough estimator\, as shown in th e displaced-null measurements theory [2]. Finally\, an optimal estimator i s computed in terms of the total number of excitations of the TIMs\, avoid ing the need for expensive estimation procedures. Details can be found in [3].\n[1] D. Yang\, S. F. Huelga\, and M. B. Plenio PRX Quantum 13\, 03101 2 (2023)\n[2] F. Girotti\, A. Godley and M. Guta\, J. Phys. A 57 245304 (2 024)\n[3] F. Girotti\, A. Godley and M. Guta\, Quantum 9\, 1835 (2025)\n15 :00-16:00  Jean-Michel Coron (Sorbonne Université\, laboratoire Jacques- Louis Lions) – Control and stabilization of partial differential equatio ns systems with essential quadratic terms\nOur focus is on exploring the c ontrollability and asymptotic stabilization of nonlinear partial different ial equations in which the quadratic term plays a crucial role. In these c ases\, both controllability and asymptotic stabilization are not achievabl e without these quadratic terms. This includes Schrödinger equations\, th e viscous Burgers equation\, Korteweg-de Vries equations and a Saint-Venan t (shallow-water) equation. Regarding controllability\, we demonstrate tha t controlling such systems may require more time than anticipated based on the speed of propagation. For the stabilization aspect\, we introduce met hodologies for designing stabilizing feedback laws. Additionally\, we pres ent unsolved challenges in these two domains.\n16:00-16:30 Coffee break\n1 6:30-17:30 Jérémie Guillaud (Alice&Bob) – Fault-tolerant quantum compu ting with dissipative cat qubits: recent theoretical and experimental prog ress.\nDissipative cat qubits\, stabilised in a superconducting circuit ar chitecture by engineered two-photon dissipation\, exhibit a very large noi se bias (up to several orders of magnitude between bit-flip and phase-flip error rates). I this talk\, I will review recent theoretical work that pr oposes to leverage this noise bias to design efficient phase-flip error co rrecting codes\, or magic state distillation factories. I will then presen t some results on recent experimental progress towards building a logical (error corrected) qubit using dissipative cat qubits.\n18:30-21:00 Cocktai l dinner\n \nFriday\, June 5\n9:00-10:00 Rémi Robin (Mines Paris PSL\, Quantic Team) – Structure-Preserving Numerical Methods for the Lindblad Master Equation\nThis talk focuses on the numerical simulation of open qua ntum systems described by the Gorini–Kossakowski–Sudarshan–Lindblad (GKSL) master equation\, with an emphasis on systems composed of a few bos onic modes. We analyze the errors introduced by the discretization of the infinite-dimensional Hilbert space\, specifically when using the truncated Fock basis\, and examine the effects of time discretization\, revealing a CFL-like stability condition that limits the time step relative to the sp atial truncation. To circumvent this constraint\, we introduce novel integ ration schemes that preserve the structure of the quantum channel evolutio n while avoiding the CFL restriction. We also propose new algorithms for s teady-state and low-lying spectrum computation\, which yield substantial c omputational gains for large bosonic systems. Part of this work is in coll aboration with G. Beugnot\, P.-L. Etienney\, P. Gregory\, P. Rouchon\, L.- A. Sellem and A. Tilloy.\n10:00-10:30 Coffee break\n10:30-11:30 Alain Sarl ette  (Inria\, Quantic Team) – Solving k-SAT problems on quantum machin es with Zeno dragging\nThe k-SAT is a prototypical NP-complete problem. Fo r these\, standard quantum computing promises just a quadratic improvement on the exponential runtime of naive exploration. Quantum annealing can al so look for a solution\, with runtime\ndepending on a not-too-well-charact erized\, but exponentially small\, spectral gap. We will first revise thes e notions\, including earlier improvements which go further than naive exp loration\, thanks to a kind of feedback action. We will then present an al ternative approach which uses Zeno dragging. Its open-loop performance (Li ndblad type equaton) seems related to quantum annealing\, but with a more straightforward bound involving the spectral gap. Including feedback impro ves the runtime and\, unlike in other schemes\, should also allow to corre ct online a particular type of quantum hardware errors. This is joint work with the group of Birgitta Whaley at U.Berkeley.\n11:30-12:30 Samuel Del église (Laboratoire Kastler Brossel) – Probing the quantum motion of a MHz mechanical resonator with a resonant rf-fluxonium\nMHz-frequency mecha nical resonators are powerful platforms for quantum technologies and tests of fundamental physics\, yet efficient control remains challenging due to their low energy scales and the difficulty of coupling them to well-contr olled quantum systems at matching frequencies. Here we demonstrate high-fi delity\, repeated interactions between a 4-MHz suspended silicon nitride m embrane resonator and a resonant superconducting fluxonium qubit. Over the membrane’s 6-ms lifetime\, the two systems coherently interact more tha n 300 times. Using the qubit as a stroboscopic spectrometer\, we reconstru ct the membrane’s position-noise spectrum\, revealing its thermal occupa tion\, qubit-induced back-action\, and the characteristic emission–absor ption imbalance. This asymmetry directly reflects the non-commutation of p honon ladder operators\, demonstrating the quantum character of the long-l ived\, massive mode. Because the predicted Diósi–Penrose collapse time is comparable to the membrane’s decoherence time\, our platform operates in a regime suitable for future interferometric tests of gravity-induced wavefunction collapse.\n12:30-14:00 Farewell lunch\n \nThis workshop is o rganised in the framework of the ERC Advanced Grant Project Q-Feedback. Th is project has received funding from the European Research Council (ERC) u nder the European Union’s Horizon 2020 research and innovation programme (grant agreement No 884762).\n \n \nDes photos/vidéos seront prises dur ant cet événement. En vous inscrivant\, vous acceptez qu'elles soient ut ilisées par Mines Paris - PSL pour toute communication (site\, compte-ren du\, rapport activités\, RS\, lettres d'information\, ...).\nSi vous vous y opposez\, merci de nous le préciser le jour de l'événement.  GEO:48.84558500000001;2.339632 LOCATION:60 Boulevard Saint-Michel 75006 Paris - FR ORGANIZER:Mines Paris - PSL END:VEVENT END:VCALENDAR