We study the relaxation dynamics of an isolated zero temperature quasi-two-dimensional superfluid Bose-Einstein condensate that is imprinted with a spatially random distribution quantum vortices. Following period vortex annihilation remaining vortices self-organize into two macroscopic coherent "Onsager vortex" clusters are stable indefinitely--despite absence driving or external dissipation in dynamics. demonstrate this occurs due to novel physical mechanism--the evaporative heating...

Interacting systems driven far from equilibrium tend to evolve steady states exhibiting large-scale structure and order. In two-dimensional turbulent flow the seemingly random swirling motion of a fluid can towards persistent vortices. Lars Onsager proposed model based on statistical mechanics quantized vortices explain such behavior. Here we report first experimental confirmation Onsager's turbulence. We drag grid barrier through an oblate superfluid Bose--Einstein condensate generate...

Topological quantum computers promise a fault tolerant means to perform computation. use particles with exotic exchange statistics called non-Abelian anyons, and the simplest anyon model which allows for universal computation by particle or braiding alone is Fibonacci model. One classically hard problem that can be solved efficiently using finding value of Jones polynomial knots at roots unity. We aim provide pedagogical, self-contained, review topological from matrices layout such computer...

Quantum mechanical simulations of neutron star rotational glitches, triggered by vortex avalanches in the superfluid stellar interior, reveal that vortices pin nonaxisymmetrically to crust during intervals between glitches. Hence a glitching emits persistent current quadrupole gravitational wave signal at star's rotation frequency, whose interglitch amplitude is constant and determined avalanche history since birth. The can be detected principle coherent searches planned for Laser...

Here we show, by performing ab initio classical field simulations that two distinct superfluid phases, separated thermal vortex-antivortex pair creation, exist in experimentally producible quasi-2D Bose gas. These results resolve the debate on nature of low temperature phase(s) a trapped interacting 2D

We derive a general and exact equation of motion for quantized vortex in an inhomogeneous two-dimensional Bose-Einstein condensate. This expresses the velocity as sum local ambient density phase gradients vicinity vortex. perform Gross-Pitaevskii simulations single-vortex dynamics both harmonic hard-walled disk-shaped traps, find excellent agreement cases with our analytical prediction. The reveal that, trap, main contribution to is induced gradient, finding that contradicts commonly quoted...

We study computationally dynamics of quantized vortices in two-dimensional superfluid Bose-Einstein condensates confined highly oblate power-law traps. have found that the formation large-scale Onsager vortex clusters prevalent steep-walled traps is suppressed by harmonic potentials. However, shape trapping potential does not appear to adversely affect evaporative heating efficiency gas. Instead, suppression can be understood terms energy configurations. Furthermore, we find...

Repulsive laser potential pulses applied to vortex lattices of rapidly rotating Bose-Einstein condensates create propagating density waves which we have observed experimentally and modeled computationally high accuracy. We a rich variety dynamical phenomena ranging from interference effects shock-wave formation anisotropic sound propagation.

We simulate a trapped quasi-two-dimensional Bose gas using classical field method. To interpret our results we identify the uniform Berezinskii-Kosterlitz-Thouless (BKT) temperature ${T}_{\text{BKT}}$ as where system phase-space density satisfies critical value. observe that fluctuations are suppressed in well above when quasicondensate forms first occurrence of degeneracy. At lower temperatures, but still ${T}_{\text{BKT}}$, development appreciable coherence prominent finite-size effect,...

An aberration corrected electron microscope is used to create diffraction catastrophes, containing arrays of intensity zeros threading vortex cores. Vortices are ascribed these using catastrophe theory, scalar integrals, and experimentally retrieved phase maps. From measured wave function phases, obtained focal-series retrieval, the orbital angular momentum density mapped for highly astigmatic probes. We observe rings topological reconnections nodal lines by tracking cores phases.

A \textit{walker} is a droplet of liquid that self-propels on the free surface an oscillating bath same through feedback between and its wave field. We have studied walking droplets in presence two driving frequencies observed new class droplets, which we coin \textit{superwalkers}. Superwalkers may be more than double size largest walkers, travel at triple speed fastest ones, enable plethora novel multi-droplet behaviors.

Multiply quantized vortices in trapped Bose-Einstein condensates are studied using the Bogoliubov theory. Suitable combinations of a localized pinning potential and an external rotation system found to energetically stabilize, both locally globally, with multiple circulation quanta. We present phase diagram for stable multiply terms angular frequency width potential. argue that multiquantum could be experimentally created suitable choice these two parameters.

We have theoretically investigated Kelvin waves of quantized vortex lines in trapped Bose-Einstein condensates. Counterrotating perturbation induces an elliptical instability to the initially straight line, driven by a parametric resonance between quadrupole mode and pair modes opposite momenta. Subsequently, rapidly decay longer wavelengths emitting sound process. present modified wave dispersion relation for superfluids propose simple method excite specific number.

We consider the inertial mass of a vortex in superfluid. obtain that is well defined and determined microscopically self-consistently by elementary excitation energy kelvon quasiparticle localized within core. The obtained result for found to be consistent with experimental observations on superfluid quantum gases rings water. propose method measure rest Berry phase Bose Fermi gases.

An algorithmic approach to assess the potential of hybrid topological quantum computers is developed, allowing one remove excess non-topological gates and reduce impact noise on compiled braid circuits.

Full, three-dimensional time-dependent simulations are presented demonstrating the quantized transfer of angular momentum to a Bose-Einstein condensate from laser carrying orbital in Laguerre-Gaussian mode. The process is described terms coherent Bragg scattering atoms chiral optical lattice. efficiency and content output coupled vortex state analyzed compared with recent experiment.

We measure the Gouy phase anomaly for matter waves using in-line holography to retrieve full complex field of an astigmatic electron wave function. Sequential shifts \ensuremath{\pi}/2 rad are observed trajectories along optic axis that pass through each line-focus caustic subnanometer transverse width. Our observations demonstrate anomalous in vicinity caustics can be robustly measured retrieval, extending current scope singular optics.

A droplet bouncing on the surface of a vertically vibrating liquid bath can walk horizontally, guided by waves it generates each impact. This results in self-propelled classical particle-wave entity. By using one-dimensional theoretical pilot-wave model with generalized wave form, we investigate dynamics this We employ different spatial forms to understand role played both oscillations and decay walking dynamics. observe steady motion as well unsteady motions such oscillating walking,...

We have performed numerical simulations of giant vortex structures in rapidly rotating Bose-Einstein condensates within the Gross-Pitaevskii formalism. reproduce qualitative features, such as oscillation core area, formation toroidal density hole, and precession vortices, observed recent experiment [Phys. Rev. Lett., ()]]. provide a mechanism which quantitatively explains phenomenon. demonstrate clear distinction between atom removal repulsive pinning potential creating vortices. In...

We investigate the harmonically trapped interacting Bose gas in a quasi-two-dimensional geometry using classical field method. The system exhibits quasi-long-range order and nonclassical rotational inertia at temperatures below Berezinskii-Kosterlitz-Thouless crossover to superfluid state. In particular, we compute scissors-mode oscillation frequencies find that irrotational mode changes its frequency as temperature is swept across thus providing microscopic evidence for emergence of superfluidity.

We propose methods to create fractional vortices in the cyclic state of an $F=2$ spinor Bose-Einstein condensate by manipulating its internal spin structure using pulsed microwave and laser fields. The stability such is studied as a function rotation frequency confining harmonic trap both pancake- cigar-shaped condensates. find range parameters for which so-called $\frac{1}{3}$ vortex energetically favorable. Such could be created condensates $^{87}\text{R}\text{b}$ atoms current...

We have studied topology and dynamics of quantum vortices in spin-2 Bose-Einstein condensates. By computationally modeling controllable braiding fusion these vortices, we demonstrated that certain such spinor condensates behave as non-Abelian anyons. identify anyons fluxon, chargeon, dyon quasiparticles. The pertinent anyon models are defined by the double underlying discrete symmetry group condensate ground state order parameter.

We introduce a new method of statistical analysis to characterize the dynamics turbulent fluids in two dimensions. establish that, equilibrium, vortex distributions can be uniquely connected temperature gas, and we apply this thermometry simulations decaying superfluid turbulence. confirm hypothesis evaporative heating leading Onsager vortices proposed Phys. Rev. Lett. 113, 165302 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.165302, find previously unidentified power-law that emerge from dynamics.

We propose a robust imaging technique that makes it possible to distinguish vortices from antivortices in quasi-two-dimensional Bose-Einstein condensates single image of the density atoms. Tilting planar condensate prior standard absorption excites generalized gyroscopic mode condensate, revealing sign and location each vortex. This is anticipated enable experimental measurement incompressible kinetic energy spectrum observation negative-temperature phase transition vortex gas, driven by...

We numerically model decaying quantum turbulence in two-dimensional disk-shaped Bose--Einstein condensates, and investigate the effects of finite temperature on turbulent dynamics. prepare initial states with a range condensate temperatures, imprint equal numbers vortices antivortices at randomly chosen positions throughout fluid. The are then subjected to unitary time-evolution within c-field methodology. For lowest results zero Gross--Pitaevskii theory reproduced, whereby vortex...