Detecting multiple temperatures Most people have an intuitive understanding of temperature. In the context statistical mechanics, higher temperature, more a system is removed from its lowest energy state. Things become complicated in nonequilibrium governed by quantum mechanics and constrained several conserved quantities. Langen et al. showed that as many 10 temperature-like parameters are necessary to describe steady state one-dimensional gas Rb atoms was split into two particular way (see...

Even though the evolution of an isolated quantum system is unitary, complexity interacting many-body systems prevents observation recurrences states for all but smallest systems. For large one can not access full and requirements to observe a recurrence in experiments reduces being close initial state with respect employed observable. Selecting observable connected collective excitations one-dimensional superfluids, we demonstrate coherence long range order containing thousands particles....

We investigate signal propagation in a quantum field simulator of the Klein-Gordon model realized by two strongly coupled parallel one-dimensional quasi-condensates. By measuring local phononic fields after quench, we observe correlations along sharp light-cone fronts. If atomic density is inhomogeneous, these fronts are curved. For edges, reflected at system's boundaries. extracting space-dependent variation front velocity from data, find agreement with theoretical predictions based on...

The formation of dispersive shock waves in one-dimensional Bose gas represents a limitation Generalized Hydrodynamics (GHD) due to the coarse-grained nature theory. Nevertheless, GHD accurately captures long-wavelength behavior, thus indicating an implicit knowledge underlying microscopic physics. Such representations are already known through Whitham modulation theory, where dispersionless equations describe evolution slowly varying wave parameters. Here we study correspondence between...

The Unruh effect predicts a thermal response for an accelerated detector moving through the vacuum. Here we propose interferometric scheme to observe analogue of circular using localized laser coupled Bose-Einstein condensate (BEC). Quantum fluctuations in are governed by effective relativistic field theory, and as demonstrated, acts Unruh-DeWitt thereof. speed light is lowered 12 orders magnitude sound velocity BEC. For detectors traveling close speed, observation system becomes...

Quantum field theory is a powerful tool to describe the relevant physics governing complex quantum many-body systems. Here, we develop general pathway extract irreducible building blocks of theoretical descriptions and its parameters purely from experimental data. This determination accomplished by extracting one-particle (1PI) correlation functions which one can construct all physical observables. To match capabilities techniques, our approach employs formulation based on equal-time only....

Interference upon free expansion gives access to the relative phase between two interfering matter waves. Such measurements can be used reconstruct spatially-resolved phase, which is a key observable in many quantum simulations of field theory and non-equilibrium experiments. However, 1D systems, longitudinal dynamics typically ignored analysis experimental data. In our work, we give detailed account various effects corrections that occur finite temperatures due expansion. We provide an...

The Unruh effect states that a uniformly linearly accelerated observer with proper acceleration $a$ experiences Minkowski vacuum as thermal state in the temperature ${T}_{\mathrm{lin}}=a/(2\ensuremath{\pi})$, operationally measurable via detailed balance condition between excitation and deexcitation probabilities. An uniform circular motion similar Unruh-type ${T}_{\text{circ}}$, condition, but ${T}_{\text{circ}}$ depends not just on also orbital radius energy. We establish analytic results...

We show that the dynamical instability of quantum vortices with more than a single unit circulation results from superradiant bound state inside vortex core. then reveal striking behavior system in nonlinear regime. Counter to expectation should produce well-separated vortices, evolves into corotating singularities orbiting within few healing lengths each other, undergoing modulations separation. During these modulations, kinetic energy is traded back and forth between sound waves vortical...

The authors present a detailed three-dimensional numerical modeling and analysis of the relaxation dynamics in an extended bosonic Josephson junction realized by two tunnel-coupled elongated superfluids double well potential.

Vortices and black holes set the scene for many interesting dynamical processes in physics. Here, we study instability of quantized vortices rotational superradiance around rotating holes, illustrating process that same physics is at play these two seemingly disparate phenomena. We also compare vortex to hole bomb instability, which occurs massive scalar fields Kerr spacetime. Taking inspiration from analogy between modes hydrogen spectrum, compared with nuclear resonances involved...

We consider the expansion of wave packets governed by free Schrödinger equation. This seemingly simple task plays an important role in simulations various quantum experiments, especially field matter-wave interferometry. The initial tight confinement particles results a very fast function at later times which significantly complicates efficient and precise numerical evaluation. In many practical cases time is too short for validity stationary phase approximation long application Fourier...

Single-particle momentum spectra for a dynamically evolving one-dimensional Bose gas are analysed in the semi-classical wave limit. Representing one of simplest correlation functions these give information about possible universal scaling behaviour. Motivated by previously discovered connection between (quasi-)topological field configurations, strong turbulence, and nonthermal fixed points quantum dynamics, soliton formation is studied with respect to appearance transient power-law spectra....

We study Floquet engineering of the tunnel coupling between a pair one-dimensional bosonic quasicondensates in tilted double-well potential. By modulating energy difference two wells, we reestablish and precisely control its amplitude phase. This allows us to initiate coherence initially uncorrelated Bose gases prepare different initial states emerging sine-Gordon Hamiltonian. fully characterize system dependence both equilibrium properties relaxation on modulation.

We present our new experimental and theoretical framework which combines a broadband superluminescent diode (SLED/SLD) with fast learning algorithms to provide speed accuracy improvements for the optimization of 1D optical dipole potentials, here generated Digital Micromirror Device (DMD). To characterize setup potential speckle patterns arising from coherence, we compare single-mode laser by investigating interference properties. employ Machine Learning (ML) tools train physics-inspired...

Quantum field theories (QFTs) as relevant for condensed-matter or high-energy physics are formulated in continuous space and time, typically emerge effective low-energy descriptions. In atomic physics, an example is given by tunnel-coupled superfluids, which realize the paradigmatic sine-Gordon model, can act quantum simulators of QFTs. To quantitatively characterize QFT simulators, to discover Hamiltonian governing dynamics a many-body system, we discuss learning method systematically...

Studying the dynamics of quantum many-body systems is often constrained by limitations in probing relevant observables, especially continuous systems. A powerful method to gain information about such reconstruction local currents from continuity equation. Here we extend this approach extract total phase fluctuation adjacent Bose gases. We validate our technique numerically and demonstrate its effectiveness analyzing data selected experiments simulating 1D field theories through difference...

We investigate wave-vortex interaction emerging from an expanding compact vortex cluster in a two-dimensional Bose-Einstein condensate. adapt techniques developed for gravitational objects to derive the characteristic modes of perturbatively around effective flow field. demonstrate existence orbits or sound-rings, analogy light-rings, and compute spectrum out-of-equilibrium cluster. The obtained numerical simulations stochastic Gross-Pitaevskii equation exhibiting is excellent agreement with...

We propose an experiment combining fluid dynamics and strong magnetic field physics to simulate cosmological scenarios. Our proposed system consists of two immiscible, weakly magnetized fluids moved through a gradient field. The diamagnetic paramagnetic forces thus generated amount time-dependent effective gravity, which allows us precisely control the propagation speed interface waves. Perturbations on therefore experience nonstationary metric. In what follows, we demonstrate that our is...

Light-matter interaction is well understood on the single-atom level and routinely used to manipulate atomic gases. However, in denser ensembles, collective effects emerge that are caused by light-induced dipole-dipole interactions multiple photon scattering. Here, we report observation of a mechanical deformation cloud ultracold Rb87 atoms due interplay homogenous light field. This scattering results self-confining potential with interesting features: It exhibits nonlocal properties,...

We study the effects of strong inter-particle interaction on diffraction a Bose-Einstein condensate ^6\mathrm{Li}_2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi /><mml:mn>6</mml:mn></mml:msup><mml:msub><mml:mstyle mathvariant="normal"><mml:mi>L</mml:mi><mml:mi>i</mml:mi></mml:mstyle><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> molecules from periodic potential created by pulses far detuned optical standing wave. For short we...