ICOLS features the latest developments in the area of laser spectroscopy and related topics in atomic, molecular, and optical physics and other disciplines. The talks covered a broad range of exciting physics, such as precision tests of fundamental symmetries with atoms and molecules, atomic clocks, quantum many-body physics with ultra-cold atoms, atom interferometry, quantum information science with photons and ions, quantum optics, and ultra-fast atomic and molecular dynamics.

Congratualtions to Sambit Pal! Congratualtions to Christian Gross! This roadmap bundles fast developing topics in experimental optical quantum sciences, addressing current challenges as well as potential advances in future research. Quantum assisted high precision measurements are discussed in the first three sections, which review optical clocks, atom interferometry, and optical magnetometry. These fields are already successfully utilized in various applied areas. We will discuss approaches to extend this impact even further. In addition, the marvelous demonstrations of systems suitable for quantum information is not progressing, unsolved challenges remain and will be discussed.

We will also review, as an alternative approach, the utilization of hybrid quantum systems based on superconducting quantum devices and ultracold atoms. Novel developments in atomtronics promise unique access in exploring solid-state systems with ultracold gases and are investigated in depth. The sections discussing the continuously fast-developing quantum gases include a review on dipolar heteronuclear diatomic gases, Rydberg gases, and ultracold plasma. Overall, we have accomplished a roadmap of selected areas undergoing rapid progress in quantum optics, highlighting current advances and future challenges.

These exciting developments and vast advances will shape the field of quantum optics in the future. We report on an efficient production scheme for a large quantum degenerate sample of fermionic lithium. This allows utilizing a large volume crossed optical dipole trap with a total power of 45 W, leading to high loading efficiency and 8x10 6 trapped atoms. The same optical trapping configuration is used for rapid adiabatic transport over a distance of 25 cm in 0. With optimized evaporation we achieve a degenerate Fermi gas with 1. Furthermore, the performance is demonstrated by evaporation near a broad Feshbach resonance creating a molecular Bose-Einstein condensate of 3x10 5 lithium dimers.

All-optical production and transport of a large 6 Li quantum gas in a crossed optical dipole trap , Ch. Gross, H. Gan, and K. Dieckmann, Phys. A, 93 , Thank you for travelling to Singapore and your contributions to a successful conference! We study the density limiting factors and in particular find a value for the light-assisted collisional loss coefficient of 1. Two-stage magneto-optical trapping and narrow-line cooling of 6 Li atoms to high phase-space density , J.

Sebastian, Ch. Gross, Ke Li, H. Gan, Wenhui Li, and K. A, 90 , Walraven, University of Amsterdam, is visiting our group from Jan until May, Throughout the semester he will teach this fully creditable module: PC "Quantum gases collisions and statistics" This course introduces basic concepts of the physics of ultra-cold quantum gases - low-density gases of neutral atoms studied at sub microkelvin temperatures.

Quantum gases are important both from the fundamental point of view and for their potential application in quantum information processing. The course is focused on quantum collisions and quantum statistics as these phenomena provide the underpinning for the very existence of the field. A systematic introduction is given into the quantum mechanics of low-energy collisions and the consequences of the quantum statistical nature of the collision partners for the behavior of the gas. The students will learn to distinguish between varieties of collisional phenomena and understand their consequences both from the kinetic and the thermodynamic point of view.

Module flyer. Zoom into our lab here. In an industry collaboration with TEM Messtechnik GmbH, Hannover, Germany, we report on a calibration procedure that enhances the precision of an interferometer based frequency stabilization by several orders of magnitude. For this purpose, the frequency deviations of the stabilization are measured precisely by means of a frequency comb. This allows us to implement several calibration steps that compensate different systematic errors.

The resulting frequency deviation is shown to be less than 5. Wide tuning of a stabilized laser at this exceptional precision is demonstrated. Calibrating an interferometric laser frequency stabilization to megahertz precision, J. Brachmann, T. Magic wavelengths for mass- and spin-imbalanced mixtures in 1D optical lattices. In a collaborative theoretical study by researchers from Munich, Innsbruck, Bologna, Lyon, Wyoming, Santa Barbara, and Singapore we present a systematic investigation of attractive binary mixtures in the presence of both spin- and massimbalance in one-dimensional setups described by the Hubbard model.

After discussing typical cold atomic experimental realizations and the relation between microscopic and effective parameters, we study several many-body features of trapped Fermi-Fermi and Bose-Bose mixtures such as density profiles, momentum distributions, and correlation functions by means of density-matrix-renormalization-group and quantum Monte Carlo simulations.

In particular, we focus on the stability of Fulde-Ferrell-Larkin-Ovchinnikov, dimer, and trimer fluids in inhomogeneous situations, as typically realized in cold gas experiments due to the harmonic confinement. We finally consider possible experimental signatures of these phases both in the presence of a finite polarization and of a finite temperature.

Dimer, trimer, and Fulde-Ferrell-Larkin-Ovchinnikov liquids in mass- and spin-imbalanced trapped binary mixtures in one dimension, M. Dalmonte, K. Dieckmann, T. Roscilde, C. Hartl, A. Feiguin, U. Schollwck, and F. Heidrich-Meisner, Phys. A 85, , For our experiments with ultracold atoms and molecules we recently installed a commercial frequency comb system that can serve as a frequency reference for multiple application lasers. The system is operating in our lab and sharing the frequency comb with two other laboratories in CQT. We are using a sub-kiloherz linewidth diode laser stabilized to a highly stable optical reference resonator design - courtesy by Max-Planck-Institute for Quantum Optics, Munich, Germany.

A popular note can be found among the CQT highlights. We investigate s-wave interactions in a two-species Fermi-Fermi mixture of 6 Li and 40 K. We develop for this case the method of cross-dimensional relaxation and find from a kinetic model, Monte Carlo simulations, and measurements that the individual relaxation rates differ due to the mass difference. The method is applied to measure the elastic cross section at the Feshbach resonance that we previously used for the production of heteronuclear molecules.

This reveals that molecules are being produced on the atomic side of the resonance within a range related to the Fermi energies, therefore establishing the first observation of a many body effect in the crossover regime of a narrow Feshbach resonance. Costa, J. Brachmann, A. Voigt, C. Hahn, M. Taglieber, T. In March we transfered the experimental setup from Munich to Singapore. The experiment had been developed in the group of Prof. Picture Gallery: Move to Singapore. We report on the first creation of ultracold bosonic heteronuclear molecules of two fermionic species, 6 Li and 40 K, by a magnetic field sweep across an interspecies s-wave Feshbach resonance.

In particular, we seek to answer fundamental questions in quantum theory as well as to engineer devices that harness quantum coherence. Recent explorations include quant. In recent decades, there has been intense interest in understanding the role of geometry in band structures. In contrast to solid state systems, where geometric effects are usually observed through the response of other quantities, ultracold atoms in optical lattices offer the unique possibility of directly probing the geometry of the band eigenstates.

Using a BEC in a graphene-type hexagonal lattice, we directly probe band geometry by combining Ramsey interferometry with a gradient. Next, using a strong gradient, we realize dynamics that are described by Wilson lines, which are generalizations of Berry phases to multiple, degenerate bands. We demonstrate that probing the evolution in band populations enables a tomographic reconstruction of the cell-periodic Bloch functions at any quasimomentum.

Previously, she received her B. Sc in physics at MIT. Two component ultra-cold bosonic gases in optical lattices are an excellent quantum simulator. We will present two examples in this talk. The first part focuses on the near perfect implementation of Heisenberg chains which is achieved using a single component Mott insulating state. Single site addressing techniques are applied to manipulate the local spin population. Quantum as well as thermal fluctuations cause a residual hole probability in the initial state and the impact on coherent spin transport is an open question.

We experimentally show that coherent spin transport under these conditions is indeed possible. Propagation of a single spin impurity results in entanglement spreading along the spin chain which we directly detect by measuring the concurrence between pairs of lattice sites.

The second part of the talk will be about many-body localization MBL. Under which conditions well isolated quantum systems do thermalize is a fundamental question. MBL marks a general class of systems which do not thermalize. Microscopic detection of diverging observables near the phase transition remains experimentally challenging, and demonstration of the MBL in higher dimensions is still demanding.

We report on recent experiments on MBL of Bosons in a two dimensional square lattice. We prepare a structured highly excited Mott insulating state which relaxes to a thermal state for vanishing disorder. A projected on-site random disorder potential changes the time evolution significantly and leads to non ergodic behavior.

Employing single site and single atom sensitivity we use local observables to quantify the dynamics of the bosonic many body state for different disorder strength. We observed the phase transition to MBL to occur only above a critical disorder strength for interacting Bosons. Immanuel Bloch. He is working at the single atom experiment on simulation of spin models and many-body dynamics.

Philipp Treutlein U. The parts of a composite system can share correlations that are stronger than any classical theory allows. These so-called Bell correlations can be confirmed by violating a Bell inequality and represent the most profound departure of quantum from classical physics. We report experiments where we detect Bell correlations between the spins of atoms in a Bose-Einstein condensate [1]. We derive a Bell correlation witness from a recent many-particle Bell inequality [2] involving one- and two-body correlation functions only.

Our measurement on a spin-squeezed state [3] exceeds the threshold for Bell correlations by 3. Concluding the presence of Bell correlations is unprecedented for an ensemble containing more than a few particles. Our work shows that the strongest possible non-classical correlations are experimentally accessible in many-body systems, and that they can be revealed by collective measurements.

This opens new perspectives for using many-body systems in quantum information tasks. Schmied, J. Bancal, B. Allard, M. Fadel, V. Scarani, P. Treutlein, N. Sangouard, to be published Tura, R. Augusiak, A. Sainz, T. Lewenstein, A. Riedel, P. Li, T. Sinatra, P. Treutlein, Nature , Short Biography Philipp Treutlein, born in Reutlingen in , studied physics at the Universities of Konstanz and Stanford in At Stanford, he worked in the laboratory of Steven Chu on laser cooling and atom interferometry.

Back in Konstanz, he joined Markus Oberthaler's group for his diploma thesis, investigating Bose-Einstein condensates in optical lattices. From , Philipp worked in the laboratory of Theodor W. During this time, he performed experiments with ultracold atoms in chip-based microtraps "atom chips". He demonstrated a chip-based atomic clock and an atom interferometer, carried out first experiments on quantum metrology with entangled atoms, and explored interfaces of atoms and mechanical oscillators. In , Philipp was appointed as a tenure-track assistant professor at the University of Basel, where he set up a group working on ultracold atoms, optomechanics, and hybrid quantum systems.

In February he was promoted to associate professor. The generation of quantum states carrying entanglement among propagating light fields and stationary matter is a prerequisite for fundamental test of quantum mechanics, such as loophole free Bell tests, as well as for applications in quantum communication over long distances. Current experiments achieve a remarkably high efficiency in generating and controlling such entangled states of matter, such as single atoms, atomic ensembles, and even with micro-mechanical oscillators, with pulsed light.

In my talk I will present our recent theoretical studies towards extending this to continuous-wave light which may provide new perspectives for experiments operating in the regime of strong cooperativity of light-matter interactions. In particular, I will show that this approach can be used to generate deterministically long-distance entanglement of material degrees of freedom, emulate many-body quantum dynamics, and perform analog variational calculations for models of quantum field theories. Mark Saffman U. Recent years have witnessed substantial progress in using interactions between Rydberg excited atoms for quantum gates and entanglement generation.

Nevertheless there remain several outstanding challenges that must be overcome to achieve scalable quantum computation. These include gate fidelity, atom loss, and quantum nondemolition state measurements without crosstalk to nearby qubits. After reviewing the current state of the art we will present some new ideas for simple solutions using complex atoms. We use nano-lithography techniques to create lattice potentials in permanent magnetic films on atom chips.

These lattices can be created over a large range of length scales and are used to trap mesoscopic clouds of ultracold atoms. In our current experiments we use a 10 micron lattice spacing to study Rydberg physics with clouds up to atoms. In parallel, we are downscaling the lattice spacing for a new series of experiments. On these new atom chips we created lattices with lattice spacing varying from nm up to 5um on the same chip.

I will discuss both the current experiments and the fabrication of these new magnetic potentials. These chips were patterned by e-beam lithography and etched with an Ar plasma to obtain structures with a 20nm resolution.

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This technique can extend the range of length scales of optical lattices to smaller scale's and therefore higher interaction energies, also it c an be used to study degenerate gases in completely engineered potential environments. In my talk I will focus on the fabrication of the magnetic chips, the construction of our new quantum gas experiment and I will show various new lattice geometries that we developed and simulated.

Dark energy could be a dynamic field - quintessence. The original and simplest model is based on so-called tracker potentials. Confirming this model would identify the dominant constituent of the universe and help understanding its history. In principle, this is possible by studying the history of the dark energy density, e.

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Assuming a coupling between dark energy and normal matter, of roughly gravitational strength, allows us to detect search for quintessence by measuring its interaction with cold atoms in atom interferometers. We have already constrained the model more than times more strongly than the best previous experiment. Searching its entire parameter space is feasible and would either detect quintessence or rule out the model, thus characterizing the properties of dark energy.

We will discuss recent developments at a new scientific interface between quantum optics, nanoscience and quantum information science. Specific examples include the use of quantum optical techniques for manipulation of individual atom-like impurities at a nanoscale and for realization of hybrid systems combining them with nanophotonic devices.

We will discuss how these techniques are used for exploring quantum nonlinear optics and quantum networks, probing non-equilibrium quantum dynamics, and developing new applications such as magnetic resonance imaging with single atom resolution, and nanoscale sensing in biology and material science. Dramatic progress has been made in the last decade and a half towards realizing solid-state systems for quantum information processing with superconducting quantum circuits.

Artificial atoms or qubits based on Josephson junctions have improved their coherence times more than a million-fold, have been entangled, and used to perform simple quantum algorithms. The next challenge for the field is demonstrating quantum error correction that actually improves the lifetimes, a necessary step for building more complex systems. Here we demonstrate a fully operational quantum error correction system, based on a logical encoding comprised of superpositions of cat states in a superconducting cavity. This system uses real-time classical feedback to encode, track the naturally occurring errors, decode, and correct, all without the need for post-selection.

Using this approach we reach, for the first time, the break-even point for QEC and preserve quantum information through active means. Moreover, the performance of the system matches with predictions, and can be dramatically improved by making the protocol more fault tolerant. Mastering the practice of error correction, and understanding the overhead and complexity required, are the main scientific challenges remaining for reaching scalable quantum computation with this technology.

Spin-squeezed states have now been created in a range of atomic systems using a variety of methods. This talk looks at some promising alternative schemes for creating spin squeezing in cavity QED systems using cavity-mediated Raman transitions to engineer effective atom-photon and atom-atom interactions.

These schemes follow on from the proposal of Dimer et al. We first examine this model in a regime where the dispersive coupling is very large and find that the steady state of the system can in fact be a strongly spin-squeezed Dicke state of the atomic ensemble. These states can offer Heisenberg-limited metrological properties and feature genuine multipartite entanglement amongst the entire atomic ensemble. We also consider a more general set of schemes, which utilise additional atomic internal electronic states or additional cavity modes to engineer alternative collective-spin models [3].

Dimer, B. Estienne, A. Parkins and H. Grimsmo and A. Parkins, Dissipative Dicke model with nonlinear atom-photon interaction, J. B: At. Morrison and A. Parkins, Collective spin systems in dispersive optical cavity QED: quantum phase transitions and entanglement, Phys. Cheng Chin U. Chicago Scaling symmetry of topological defects in quantum critical dynamics. Spanning condensed matter, cosmology, and quantum gases, evolution of many-body systems is hy-pothesized to be universal near a continuous phase transition.

A long-sought signature of the universal dynamics is the scaling symmetry of emerging topological defects; examples include cosmic domains in early universe T. Kibble, , and vortices in quenched superfluid helium W. Zurek, We test the scaling symmetry and universality of quantum critical dynamics based on Bose-Einstein condensates of cesium atoms ramping across an effective ferromagnetic quantum phase transition. We observe a sudden growth of quantum fluctuations and domains separated by topological defects domain walls.

Intriguingly, the domains are anti-ferromagnetically ordered with record thermal energy scales as low as kB x 20pK. Time and length scales measured over a wide range of parameters yield precise temporal and spatial critical exponents of 0. In the scaled space-time coordinate, correlations collapse to a single curve, in support of the universality hypothesis. Understanding how an isolated many-body state thermalizes and develops entropy is foundational to quantum statistical mechanics, yet appears antithetical to basic notions that we have about entropy.

An evolving quantum state can develop observables that agree with thermal ensembles, yet the unitarity of quantum evolution preserves the purity of this full quantum state in time. Hence, a pure, and in this sense, zero entropy quantum state can dynamically become seemingly entropic and thermal. In this talk, I will describe our experimental studies of thermalization in a verifiably pure many-body state, and how the entropy induced by entanglement facilitates thermalization.

I will describe our experimental method for measuring quantum purity, and thereby entanglement entropy, through the interference of two copies of a many-body state. By comparing the entanglement entropy we measure to the thermal entropy expected from an ensemble, I will illustrate how thermalization is manifest locally within a globally pure quantum state, and how these observations are related to the Eigenstate Thermalization Hypothesis.

A Many-Body Localized MBL system describes a generic phase of matter which, even with an infinite number of degrees of freedom, fails to thermalize. Surprisingly, this breakdown of thermalization can occur even in highly exited states.

As such, this phase cannot be described by conventional quantum-statistical physics which assumes an underlying temperature of the many-body system. In this talk, I will describe how can one can use a highly controllable system of ultracold atoms in optical lattices to understand and probe such a quantum many-body system. Disorder turns out to be the key ingredient in realizing the insulating MBL state.

One important challenge here is to understand the transition from a delocalized phase to the MBL phase as the disorder strength is increased. As the notion of temperature itself gets blurred, I will describe a novel method to probe ergodicity breaking based on the relaxation of local observables. I would put special emphasis on the relaxation at the MBL critical point where we observe critically slowed dynamics and will comment of the notions of Griffiths phases. If time permits, I will also show some recent results on the observation of a Floquet-MBL phase and on the possibility of MBL in two dimensions using quasi-crystals.

Stanford Photonics Research Center Symposium. Jonathan Simon U. Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0. This high fidelity is due to interference between the moving excitation and the unperturbed initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space de-novo movies of atomic motion on Angstrom and femtosecond scales.

This x-ray interference has not been employed to image atomic motion in molecules before. Coherent vibrational motion and dispersion, dissociation, and rotational dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods. One of the possibilities is that DM can be composed from ultralight quantum fields whose self-interactions lead to the formation of DM objects in the form of stable topological defects. By mining over a decade of archival GPS data, we find no evidence for topological defects in the form of domain walls at our current sensitivity, which enables us to improve the present limits on certain DM--ordinary matter coupling strengths by up to six orders of magnitude.

Cavity-polaritons have emerged as an exciting platform for studying interacting bosons in a driven-dissipative setting. Typically, the experimental realization of exciton-polaritons is based on undoped GaAs quantum wells QW embedded in between two monolithic distributed Bragg reflector DBR layers. Introduction of a degenerate electron gas either to the QW hosting the excitons or a neighboring layer substantially enriches the physics due to polariton-electron coupling.

It has been proposed that such an interacting Bose-Fermi mixture can be used to study polariton-mediated superconductivity in a two dimensional electron gas.

## Quantum Simulation with Ultracold Atomic Gases in an Optical Lattice | NTT Technical Review

Transition metal dichalcogenide TMD monolayers, such as molybdenum diselenide MoSe2 , represent a new class of valley semiconductors exhibiting novel features such as strong Coulomb interactions, finite exciton Berry curvature with novel optical signatures and locking of spin and valley degrees of freedom due to large spin-orbit coupling. In contrast to quantum wells or two-dimensional electron systems in III-V semiconductors, TMD monolayers exhibit an ultra-large exciton binding energy of order meV and strong trion peaks in photoluminescence that are red-shifted from the exciton line by 30 meV.

In this talk, he will present cavity spectroscopy of gate-tunable monolayer MoSe2 and show that in the limit of perturbative cavity coupling elementary optical excitations in this system are attractive and repulsive exciton-polarons - excitons dressed by Fermi sea electron-hole pairs. By reducing the cavity length, they reach the strong-coupling limit of cavity-QED and observe polariton formation in both attractive and repulsive branches: this constitutes a new regime of polaron physics where the polariton impurity mass is much smaller than that of the itinerant electrons.

Their findings constitute a first step in investigation of a new class of degenerate Bose-Fermi mixtures consisting of polaritons and electrons. We describe recent work at NIST to develop precision instruments based on atomic spectroscopy, advanced semiconductor lasers and micro-electro-mechanical systems MEMS.

These millimeter-scale instruments achieve take their high stability or sensitivity from the use of atomic spectroscopy, but have considerably reduced power consumption and potentially reduced manufacturing cost compared to their larger counterparts. Physics packages for atomic frequency references with fractional frequency stabilities in the range of over one hour have been demonstrated. The design, fabrication and performance of these instruments will be described, as well as a number of applications to which the devices are well-suited. Finally, we speculate on possible future directions for chip-scale atomic instrumentation with a focus on the use of laser-cooled atomic samples and tools for fundamental metrology.

Biography Dr. John Kitching received his PhD. His research interests include miniaturized atomic clocks and sensors and applications of semiconductor lasers and micromachining technology to problems in atomic physics and frequency control. He has published over 80 papers in refereed journals, has given numerous invited and plenary talks and has been awarded six patents. Cindy Regal University of Colorado, Boulder Improving broadband displacement detection via correlations with a mechanical membrane. The pursuit of increasingly sensitive interferometric measurement of mechanical motion has a rich history.

This pursuit has resulted in the development and study of seminal ideas on quantum limits of measurement and how to improve measurements in the face of seeming limitations. In recent years, an interesting class of devices has been developed in which low-mass, high-frequency, and mechanically isolated objects are coupled to optical cavities.

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The large response of these mechanical objects to applied forces makes them an ideal platform to observe the effects of radiation forces. We can now cool mechanical membranes well into their quantum ground state and routinely observe the effect of a fluctuating radiation pressure force due to optical shot noise. Our recent measurements study a technique to improve interferometric displacement detection known as variational readout. Emine Altuntas Yale University.

Trapped antimatter particles and atoms open the way to extremely precise comparisons of antimatter and matter - made to test the most fundamental symmetry of the Standard Model. Atom interferometry in microgravity promises a major leap in improving precision and accuracy of matter-wave sensors [1].

When taking advantage of the unique space environment, fundamental tests challenging the state-of-the-art can be performed using quantum gases systems. Satellite mission scenarios achieving these goals will be presented. The use of cold atoms as a source for such sensors poses; however, intrinsic challenges mainly linked to the samples size and mixture dynamics in case of a dual-atomic test.

Proposals to mitigate leading systematics in projects involving extensive interferometry times are discussed in this talk as well. Novel methods of quantum engineering at lowest energy scales developed within the droptower experiments and sounding rocket missions are presented in this context []. References [1] N. Gaaloul, et al. Aguilera et al. Quantum Grav. Rudolph et al. New J. Abend et al. After an advanced diploma in fundamental physics in , he moved to University Paris-sud where he pursued master and doctoral studies.

In , he obtained a doctoral title with a research thesis on theoretical manipulation of cold atoms with laser light. His main research focus at the moment is on dynamics of quantum gases in extended time offered by micro-gravity platforms. He is involved in several German, European and international space missions aiming to test fundamental theories of physics by performing atom interferometry experiments.

Abstract: In this talk I will discuss several examples of interesting universal dynamics with quantum simulation. This dynamics reveals the scaling symmetry and the emergent conformal symmetry of strongly interacting quantum system. In the second example, I will discuss quench dynamics from a topological trivial Chern insulator to a topological nontrivial one, and we show how to extract a quantized value from the quench dynamics, that exactly equals to the topological Chern number of the final Hamiltonian after the quench.

In the third example, I will prove a theorem that relates the entropy growth after a quench to the out-of-time-ordered correlation that recently discussed in the content of quantum chaos and holographic duality. This three examples reveal the interplay between quantum dynamics with symmetry, topology and entropy, respectively. AMO special group Meeting Mark Kasevich research group Prof.

Monika Schleier-Smith research group Prof. Jason Hogan research group. Thomas Juffmann Laboratoire kastler brossel, ENS, Paris Multi-pass microscopy - approaching Heisenberg limited sensitivity in optical and electron microscopy. The number of biological macromolecules with a structure solved by cryogenic-electron microscopy cryo-EM increases dramatically each year.

However, many small and weakly scattering protein structures remain out of reach, as electron dose induced specimen damage limits the achievable spatial resolution [1]. Improved sensitivity and spatial resolution can be obtained employing quantum measurement strategies. A quantum optimal approach to measuring small phase shifts, as induced by a thin protein, is to pass each probe particle through the specimen multiple times [2].

Employing self-imaging cavities, this idea can be applied to widefield microscopy [3]. We show post-selected optical birefringence and absorption measurements beyond the shot-noise limit and discuss the applicability of multi-pass microscopy to cryo-EM. Our EM simulations [4] show that multi-pass TEM allows for a tenfold damage reduction in imaging small proteins. Methods, 13, 1, More than 30 years ago, Richard Feynman outlined the visionary concept of a quantum simulator for carrying out complex physics calculations.

Today, his dream has become a reality in laboratories around the world. In my talk I will focus on the remarkable opportunities offered by ultracold quantum gases trapped in optical lattices to address fundamental physics questions ranging from condensed matter physics over statistical physics to high energy physics with table-top experiment. I will also show, how recent experiments with cold gases in optical lattices have enabled to realise and probe artificial magnetic fields that lie at the heart of topological energy bands in a solid, including Thouless charge pumps in multiple dimensions.

Finally, I will discuss our recent experiments on novel many-body localised states of matter that challenge our understanding of the connection between statistical physics and quantum mechanics at a fundamental level. Ehud Altman UC Berkeley Quantum thermalization and many-body localization: new insights from theory and experiments with ultra-cold atoms. Recent theoretical work has uncovered surprising richness in the dynamics of strongly interacting quantum systems, defining new classes of dynamics ranging from many-body localization to maximally chaotic behavior.

This progress has highlighted fundamental open questions including, for example, the nature of the many body localization phase transition as well as the relation between quantum chaos and hydrodynamic modes in thermalizing systems. In this talk I will focus on how experiments with ultra-cold atoms can help address some of these questions. First, I will review recent progress in confronting the emerging theoretical picture of the MBL phase and phase transition with experimental tests.

Then, I will turn to describe a new approach to compute the long time dynamics of thermalizing systems using tensor networks, allowing to compute both hydrodynamic transport properties and characteristics of quantum chaos. I will discuss proposals to test these results in experiments. Ultracold quantum gases in optical lattices provide a unique platform for the study of tailored many-body systems. The realization of quantum gas microscopes marked a new era in this field.

They enabled the precision detection of single atoms on individual lattice sites and with this provide direct experimental access to non-local correlation functions. Here we summarize the experimental progress with this new platform, where experiments evolved from textbook like studies in conceptually simple settings towards precisely controlled studies in computationally inaccessible regimes. We discuss recent results on many-body localization in two dimensions as well as on string correlations in Fermi-Hubbard chains.

Reaching dual superfluidity in helium mixtures has long been one of low-temperature physics holy grails. However, this long sought goal has been thwarted by the repulsive interactions between the two isotopes that leads to their demixion at low temperature. In ultracold atoms, the possibility offered by Feshbach resonances of tuning the strength of interatomic interactions has allowed us to cool a mixture of 6Li and 7Li into a regime where the mixture is stable and both species are superfluid.

We have proved their superfluid behaviour by creating a counterflow between the two species. We have demonstrated the existence suggesting the existence of a novel damping mechanism generalizing Landau's scenario to superfluid mixtures. More recently, we have shown that probing the inelastic decay of the mixture could be used as a quantitative probe of the short range correlation of a many-body system. Bay Area Cold Atom Meeting. Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium.

I will present results from two experiments investigating driven quantum gases. The first experiment aims to realize a nontrivial Floquet phase of matter in a strongly amplitude-modulated optical lattice. The new phase can be understood as a many-body quantum-mechanical analogue of an inverted Kapitza pendulum. The second experiment uses trapped degenerate strontium as a quantum emulator of ultrafast atom-light interactions.

Here the low energy scales of cold atom experiments give rise to an effective temporal magnification factor of eleven orders of magnitude, enabling the study of nonequilibrium dynamics relevant to attosecond-scale electronic phenomena. This problem appears in different areas of science, and several methods have been developed in fields of quantum chemistry, condensed matter and high energy physics in order to circumvent it in certain situations. In the last years, other approaches inspired by quantum information theory have been introduced in order to address such a problem.

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On the one hand, quantum simulation uses a different system in order to emulate the behavior of the problem under study. On the other, tensor networks aim at the accurate description of many-body quantum states with few parameters. In this talk, I will give a basic introduction to those approaches, and explain current efforts to use them in order to attack both condensed and high-energy physics problems. In he also became honorary professor at the Technical University of Munich.