A5061550084- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum chaos and dynamical systems
- Theoretical and Computational Physics
- Random lasers and scattering media
- Spectroscopy and Quantum Chemical Studies
- Strong Light-Matter Interactions
- Quantum optics and atomic interactions
- Quantum and electron transport phenomena
- Neural Networks and Reservoir Computing
- Opinion Dynamics and Social Influence
- Nonlinear Dynamics and Pattern Formation
- Physics of Superconductivity and Magnetism
- Quantum Information and Cryptography
- Mechanical and Optical Resonators
- Quantum, superfluid, helium dynamics
- stochastic dynamics and bifurcation
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Quantum Mechanics and Applications
- Nonlinear Photonic Systems
- Advanced Thermodynamics and Statistical Mechanics
- Chaos control and synchronization
- Advanced Chemical Physics Studies
- Advanced Fiber Laser Technologies
Heidelberg University
2019-2024
Centre National de la Recherche Scientifique
2015-2024
Laboratoire de Physique des Lasers, Atomes et Molécules
2015-2024
Université de Lille
2018-2024
We use the resonant dipole-dipole interaction between Rydberg atoms and a periodic external microwave field to engineer XXZ spin Hamiltonians with tunable anisotropies. The are placed in 1D 2D arrays of optical tweezers, allowing us study iconic situations physics, such as implementation Heisenberg model square arrays, transport 1D. first benchmark Hamiltonian engineering for two atoms, then demonstrate freezing magnetization on an initially magnetized array. Finally, we explore dynamics...
Dimension 2 is expected to be the lower critical dimension for Anderson localization in a time-reversal-invariant disordered quantum system. Using an atomic quasiperiodic kicked rotor---equivalent two-dimensional Anderson-like model---we experimentally study and we observe localized wave function dynamics. We also show that length depends exponentially on disorder strength anisotropy quantitative agreement with predictions of self-consistent theory 2D localization.
Controlling interactions is the key element for quantum engineering of many-body systems. Using time-periodic driving, a naturally given Hamiltonian closed system can be transformed into an effective target that exhibits vastly different dynamics. We demonstrate such Floquet with spins represented by Rydberg states in ultracold atomic gas. By applying sequence spin manipulations, we change symmetry properties Heisenberg XYZ Hamiltonian. As consequence, relaxation behavior total drastically...
Anderson localization, the absence of diffusion in disordered media, draws its origins from destructive interference between multiple scattering paths. The localization properties systems are expected to be dramatically sensitive their symmetry characteristics. So far however, this question has been little explored experimentally. Here, we investigate realization an artificial gauge field a synthetic (temporal) dimension disordered, periodically-driven (Floquet) quantum system. Tuning...
We study experimentally a quantum kicked rotor with broken parity symmetry, supporting ratchet effect due to the presence of classical accelerator mode. show that short-time dynamics is very well described by dynamics, characterized strongly asymmetric momentum distribution directed motion on one side, and an anomalous diffusion other. At longer times, effects lead dynamical localization, causing asymptotic resymmetrization wave function.
We report the first experimental observation of time-driven phase transition in a canonical quantum chaotic system, kicked rotor. The bears firm analogy to thermodynamic transition, with time mimicking temperature and expectation rotor's kinetic energy free energy. signals sudden change system's memory behavior: before critical time, system undergoes motion space its initial states is erased course time; after interference enhances probability for trajectory return state, thus recovered.
We study the out-of-equilibrium dynamics in quantum Ising model with power-law interactions and positional disorder. For arbitrary dimension $d$ interaction range $\alpha \geq d$ we analytically find a stretched exponential decay of global magnetization ensemble-averaged single-spin purity stretch-power $\beta = d/\alpha$ thermodynamic limit. Numerically, confirm that glassy behavior persists for finite system sizes sufficiently strong identify dephasing between disordered coherent pairs as...
We report on the observation of coherent enhancement return probability [``enhanced to origin'' (ERO)] in a periodically kicked cold-atom gas. By submitting an atomic wave packet pulsed, shifted, laser standing wave, we induce oscillation ERO time that is explained terms periodic, reversible dephasing weak-localization interference sequences responsible for ERO. Monitoring temporal decay ERO, exploit its quantum-coherent nature quantify decoherence rate system.
An important step towards a comprehensive understanding of far-from-equilibrium dynamics quantum many-body systems is the identification unifying features that are independent microscopic details system. We experimentally observe such robust in magnetization relaxation disordered Heisenberg XX, XXZ, and Ising Hamiltonians. realize these spin models with tunable anisotropy parameter power-law interactions an ensemble Rydberg atoms by encoding suitable state combinations. consistently...
We predict a resonant enhancement of the nonlinear optical response an interacting Rydberg gas under conditions electromagnetically induced transparency. The originates from two-photon process which resonantly couples electronic states pair atoms dressed by strong control field. calculate for three-level system explicitly including dynamics intermediate state. find analytical expression third order susceptibility weak classical probe absorption displays strongest behavior on resonance where...
The engineering of localized modes in photonic structures is one the main targets modern photonics. An efficient strategy to design these use interplay constructive and destructive interference periodic lattices. This mechanism at origin defect bandgaps, bound states continuum, compact flat bands. Here, we show that lattices lossy resonators, addition external optical drives with a controlled phase enlarges possibilities manipulating effects allows for novel types modes. Using honeycomb...
We numerically study out-of-equilibrium dynamics in a family of Heisenberg models with $1/{r}^{6}$ power-law interactions and positional disorder. Using the semiclassical discrete truncated Wigner approximation (dTWA) method, we investigate time evolution magnetization ensemble-averaged single-spin purity for strongly disordered system after initializing an state. find that both quantities display robust glassy behavior almost any value anisotropy parameter Hamiltonian. Furthermore,...
The atomic Quantum Kicked Rotor is an outstanding "quantum simulator" for the exploration of transport in disordered quantum systems. Here we study experimentally phase-shifted kicked rotor, which show to display properties close ideal system, opening new windows into Anderson physics.
We experimentally investigate the nonlinear transmission spectrum of coherent light fields propagating through a Rydberg EIT medium with strong atomic interactions. In contrast to previous investigations, which have largely focused on resonant control fields, we explore here full two-dimensional spectral response gas. Our measurements confirm previously observed features for vanishing control-field detuning, but also reveal significant differences two-photon resonance. particular, find...
Anderson localization is the ubiquitous phenomenon of inhibition transport classical and quantum waves in a disordered medium. In dimension one, it well known that all states are localized, implying distribution an initially narrow wave-packet released potential will, at long time, decay exponentially on scale length. However, exact shape stationary localized differs from purely exponential profile has been computed almost fifty years ago by Gogolin. Using atomic kicked rotor, paradigmatic...
Understanding how closed quantum systems dynamically approach thermal equilibrium presents a major unresolved problem in statistical physics. Generically, non-integrable are expected to thermalize as they comply with the Eigenstate Thermalization Hypothesis. However, presence of strong disorder, dynamics can possibly slow down degree that fail on experimentally accessible timescales, spin glasses or many-body localized systems. In general, particularly long-range interacting systems,...
An important step towards a comprehensive understanding of far-from-equilibrium dynamics quantum many-body systems is the identification unifying features that are independent microscopic details system. We experimentally observe such robust in magnetization relaxation disordered Heisenberg XX-, XXZ- and Ising Hamiltonians. realize these spin models with tunable anisotropy parameter power-law interactions an ensemble Rydberg atoms by encoding suitable state combinations. consistently...