Matter waves inside periodic potentials are well known from solid-state physics, where electrons interacting with a crystal lattice considered. Atomic Bose-Einstein condensates light-induced (optical lattices) share many features in solids, but also light nonlinear materials and other systems. Generally, atom-atom interactions lead to rich interesting effects. Furthermore, the experimental control over parameters of potential condensate make it possible enter regimes inaccessible In this...

We report on measurements of dynamical suppression interwell tunneling a Bose-Einstein condensate (BEC) in strongly driven optical lattice. The strong driving is sinusoidal shaking the lattice corresponding to time-varying linear potential, and measured by letting BEC freely expand rate reduced and, for certain values parameter, completely suppressed. Our results are excellent agreement with theoretical predictions. Furthermore, we have verified that, general, does not destroy phase...

We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency difference between two lattice beams. For small values of well depth, Bloch oscillations were observed. Reducing potential depth further, Landau-Zener tunneling out lowest band, leading to a breakdown oscillations, was also studied used as probe for effective resulting from mean-field interactions predicted Choi Niu [Phys. Rev. Lett. 82, 2022 (1999)]....

We demonstrate experimentally that matter waves can be coherently and adiabatically loaded controlled in one-, two-, three-dimensional strongly driven optical lattices. This coherent control is then used order to reversibly induce the superfluid-Mott insulator phase transition by changing strength of driving. Our findings pave way for studies quantum systems new methods controlling waves.

We have observed tunneling suppression and photon-assisted of Bose-Einstein condensates in an optical lattice subjected to a constant force plus sinusoidal shaking. For sufficiently large force, the ground energy levels are shifted out resonance is suppressed; when shaking switched on, coupled by low-frequency photons resumes. Our results agree well with theoretical predictions demonstrate usefulness lattices for studying solid-state phenomena.

We report on the experimental observation of dynamic localization a Bose-Einstein condensate in shaken optical lattice, both for sinusoidal and square-wave forcing. The formulation this effect terms quasienergy band collapse, backed by excellent agreement observed collapse points with theoretical predictions, suggests feasibility systematic engineering.

We report experimental results on the properties of Bose-Einstein condensates in one-dimensional optical lattices. By accelerating lattice, we observed Bloch oscillations condensate lowest band, as well Landau-Zener (LZ) tunneling into higher bands when lattice depth was reduced and/or acceleration increased. The dependence LZ rate density then related to mean-field effects modifying effective potential acting condensate, yielding good agreement with recent theoretical work. also present...

Ultracold gases excited to strongly interacting Rydberg states are a promising system for quantum simulations of many-body systems. For off-resonant excitation such systems in the dissipative regime, highly correlated exhibiting, among other characteristics, intermittency and multimodal counting distributions expected be created. Here we report on realization gas rubidium atoms measurement its full statistics phase diagram both resonant excitation. We find bimodal regime that compatible with...

We experimentally realize Rydberg excitations in Bose-Einstein condensates of rubidium atoms loaded into quasi-one-dimensional traps and optical lattices. Our results for expanded to different sizes the one-dimensional trap agree well with intuitive picture a chain excitations. also find that lattice do not destroy phase coherence condensate, our system localized collective including nearest-neighbor blockade.

Using a simple model for nonlinear Landau-Zener tunneling between two energy bands of Bose-Einstein condensate in periodic potential, we find that the rates directions are not same. Tunneling from ground state to excited is enhanced by nonlinearity, whereas opposite direction it suppressed. These findings confirmed numerical simulations dynamics. Measuring rubidium atoms an optical lattice, have found experimental evidence this asymmetry.

We report time-resolved measurements of Landau-Zener tunneling Bose-Einstein condensates in accelerated optical lattices, clearly resolving the steplike time dependence band populations. Using different experimental protocols we were able to measure probability both adiabatic and diabatic bases system. also experimentally determine contribution momentum width Bose temporal steps discuss implications for measuring jump problem.

Nonequilibrium dynamics with controllable kinetic constraints are experimentally realized cold interacting Rydberg gases. The blockade and facilitation shown to lead strikingly different dynamical evolutions of the excitations.

We report on measurements of resonantly enhanced tunneling Bose-Einstein condensates loaded into an optical lattice. By controlling the initial conditions our system we were able to observe resonant in ground and first two excited states lattice wells. also investigated effect intrinsic nonlinearity condensate resonances.

The dipole blockade of Rydberg excitations is a hallmark the strong interactions between atoms in these high-lying quantum states [M. Saffman, T. G. Walker, and K. M\o{}lmer, Rev. Mod. Phys. 82, 2313 (2010); D. Comparat P. Pillet, J. Opt. Soc. Am. B 27, A208 (2010)]. One consequences suppression fluctuations counting statistics excitations, which some evidence has been found previous experiments. Here we present experimental results on dynamics ultracold rubidium both off resonance, exhibit...

Understanding and probing phase transitions in non-equilibrium systems is an ongoing challenge physics. A particular instance are that occur between a non-fluctuating absorbing phase, e.g., extinct population, one which the relevant order parameter, such as population density, assumes finite value. Here we report observation of signatures transition open driven quantum system. In our experiment rubidium atoms quasi one-dimensional cold disordered gas laser-excited to Rydberg states under...

Highly excited Rydberg atoms are a powerful platform for quantum simulation and information processing. Here, we propose atomic ring networks to study chiral currents of excitations. The controlled by phase pattern imprinted via Raman scheme can persist even in the presence dephasing. Depending on interplay between Rabi coupling states dipole-dipole atom interaction, current shows markedly different features. excitations propagate with velocity displaying characteristic peak time, reflecting...

By accelerating a Bose-Einstein condensate in controlled way across the edge of Brillouin zone 1D optical lattice, we investigate stability vicinity edge. Through an analysis visibility interference pattern after time-of-flight and widths peaks, characterize onset instability as acceleration lattice is decreased. We briefly discuss significance our results with respect to recent theoretical work.

We present experimental results on the preparation of a desired quantum state in two-level system with maximum possible fidelity using driving protocols ranging from generalizations linear Landau-Zener protocol to transitionless that ensure perfect following instantaneous adiabatic ground state. also study minimum time needed achieve target and explore compare robustness some against parameter variations simulating uncertainty. In our experiments, we realize model Bose-Einstein condensates...

We report on the direct measurement in real space of effect van der Waals forces between individual Rydberg atoms their external degrees freedom. Clusters with interparticle distances around $5\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$ are created by first generating a small number seed excitations magneto-optical trap, followed off-resonant excitation that leads to chain facilitated events. After variable expansion time field ionized, and from arrival distributions size cluster...

Networks of Rydberg atoms provide a powerful basis for quantum simulators and technologies. Inspired by matter-wave atomtronics, here we engineer switches, diodes, universal logic gates composed networks. Our schemes control the dynamics excitation via antiblockade or facilitation mechanism, allowing much faster devices compared to cold atom systems. approach is robust noise can be applied individually trapped extensive three-dimensional gases. In analogy electronics, atomtronic promise...

Our realistic numerical results show that the fundamental and higher-order quantum resonances of delta-kicked rotor are observable in state-of-the-art experiments with a Bose condensate shallow harmonic trap, kicked by spatially periodic optical lattice. For stronger confinement, interaction-induced destruction resonant motion oscillator is predicted.

We report on measurements of the collisional properties a mixture $^{133}$Cs and $^{87}$Rb atoms in magnetic trap at $\mu\mathrm{K}$ temperatures. By selectively evaporating Rb using radio-frequency field, we achieved sympathetic cooling Cs down to few $\mu\mathrm{K}$. The inter-species cross-section was determined through rethermalization measurements, leading an estimate $a_s=595 a_0$ for s-wave scattering length $|F=2, m_F=2>$ $|F=4, m_F=4>$ states. briefly speculate prospects reaching...

In this paper, we present the theoretical as well experimental results on resonantly enhanced tunneling of Bose–Einstein condensates in optical lattices both linear case and for small nonlinearities. Our demonstrate usefulness simulating Hamiltonians originally used describing solid-state phenomena.

A comprehensive study of the tunneling dynamics a Bose--Einstein condensate in tilted periodic potential is presented. We report numerical and experimental results on time-resolved measurements Landau--Zener ultracold atoms introduced by tilt, which experimentally realized accelerating lattice. The use different protocols enables us to access probability, numerically as well experimentally, two bases, namely, adiabatic basis diabatic basis. corresponds eigenstates lattice, one free-particle...