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The production of quantised vortices having diverse structures is the remarkable effect of rotating Bose–Einstein condensates (BEC). Vortex formation described by the mean-field theory is valid only in the regime of weak interactions. The exploration of the rich and diverse physics of strongly interacting BEC requires a more general approach. This study explores the vortex states of strongly interacting and rapidly rotating BEC from a general ab-initio many-body perspective. We demonstrate that the quantised vortices form various structures that emerge from an intricate interplay between the angular momentum and many-body interaction. We examine the distinct impact of the angular velocity and interaction energy on the vortex formation. Our analysis shows that, while the angular rotation generally augments the vortex formation, the interactions can enhance as well as impede the vortex production. [ABSTRACT FROM AUTHOR]

The development and deployment of the next generation of wind energy systems calls for simulation tools that model the entire wind farm while balancing accuracy and computational cost. A full-system wind farm simulation must consider the atmospheric inflow, the wakes and consequent response of the multiple turbines, and the implementation of the appropriate farm-collective control strategies that optimize the entire wind farm's output. In this article, we present a novel vortex lattice model that enables the effective representation of the complex vortex wake dynamics of the turbines in a farm subject to transient inflow conditions. This work extends the capabilities of our multi-physics suite, CODEF, to include the capability to simulate the wakes and the high-fidelity aeroelastic response of multiple turbines in a wind farm. Herein, we compare the results of our GVLM technique with the LiDAR measurements obtained at Sandia National Laboratories' SWiFT facility. The comparison shows remarkable similarities between the simulation and field measurements of the wake velocity. These similarities demonstrate our model's capabilities in capturing the entire wake of a wind turbine at a significantly reduced computational cost as compared to other techniques. [ABSTRACT FROM AUTHOR]

We investigate the vortex lattice configuration in a rotating spin orbit-coupled spin-2 Bose–Einstein condensate confined in a quasi-two-dimensional harmonic trap. By considering the interplay between rotation frequency, spin–orbit couplings, and interatomic interactions, we explore a variety of vortex lattice structures emerging as a ground state solution. Our study focuses on the combined effects of spin–orbit coupling and rotation, analyzed by using the variational method for the single-particle Hamiltonian. We observe that the interplay between rotation and Rashba spin–orbit coupling gives rise to different effective potentials for the bosons. Specifically, at higher rotation frequencies, isotropic spin–orbit coupling leads to an effective toroidal potential, while fully anisotropic spin–orbit coupling results in a symmetric double-well potential. To obtain these findings, we solve the five coupled Gross–Pitaevskii equations for the spin-2 BEC with spin–orbit coupling under rotation. Notably, we find that the antiferromagnetic, cyclic, and ferromagnetic phases exhibit similar behavior at higher rotation. [ABSTRACT FROM AUTHOR]

The discovery of nematic triplet superconductivity in doped topological insulators CuxBi2Se3 triggers interest in the identification of the d-vector of the triplet, which is related to the antinodal direction of the gap function and determines whether the superconductor is topological. We perform self-consistent analysis of the vortex state properties in a nematic spin-triplet px-wave superconductor. We first derive a Ginzburg-Landau theory to determine the shape of the vortex and vortex lattice. We find the spatial profile of the isolated vortex is elongated along the antinodal direction, and the vortex lattice is a distorted triangular lattice elongated along x, becoming square in the specific case of a small circular Fermi surface. Finally, we calculate the local density of states self-consistently for an isolated vortex and the vortex lattice using the microscopic Bogoliubov-de Gennes equation. We find that the profile of the local density of states at low in-gap energies is always elongated along the antinodal direction. Our findings are valuable for the experimental detection of the antinodal direction of the gap function in nematic triplet superconductors, and subsequently the identification of the topological character of the superconducting state as in CuxBi2Se3. [ABSTRACT FROM AUTHOR]

• The new exact solutions of the (3 + 1)-dimensional nonlinear charney–obukhov equation in the case of "separation" of variables • A lattice of vortices with the inclination of vortex cells in the meridional plane. • Dependence of the inclination angle on the depth. • Structural stability of the vortex lattice when a cylindrically symmetric disturbance is included. Exact solutions describing Rossby waves and vortices in ocean propagating along the zonal direction at a constant velocity are considered for the (3 + 1) -dimensional nonlinear Charney – Obukhov equation. We give examples of solutions of the Charney-Obukhov equation that satisfy the nonlinear boundary conditions for the ocean, for a special case that corresponds to the "separation" of variables. The following example is considered: a lattice of vortices with 3D flow in lattice cells, the inclination of vortex cells in the meridional plane, and the dependence of the inclination angle on depth. [ABSTRACT FROM AUTHOR]

We provide the superconducting density of states of the pnictide superconductor LaRu 2 P 2 ( T c = 4.1 K), measured using millikelvin scanning tunneling microscopy. From the tunneling conductance, we extract a density of states which shows the opening of a s-wave single superconducting gap. The temperature dependence of the gap also follows BCS theory. Under magnetic fields, vortices present Caroli de Gennes Matricon states, although these are strongly broadened by defect scattering. From the vortex core size we obtain a superconducting coherence length of ξ  = 50 nm, compatible with the value extracted from macroscopicHc2measurements. We discuss the comparison between s-wave LaRu 2 P 2 and pnictide unconventional multiple gap and strongly correlated Fe based superconductors., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

On-demand generation and reshaping of arrays of focused laser beams is highly desired in many areas of science and technology. In this work, we present a versatile approach for laser beam structuring in the focal plane of a lens by triple mixing of square and/or hexagonal optical vortex lattices (OVLs). In the artificial far field the input Gaussian beam is reshaped into ordered arrays of bright beams with flat phase profiles. This is remarkable, since the bright focal peaks are surrounded by hundreds of OVs with their dark cores and two-dimensional phase dislocations. Numerical simulations and experimental evidences for this are shown, including a broad discussion of some of the possible scenarios for such mixing: triple mixing of square-shaped OVLs, triple mixing of hexagonal OVLs, as well as the two combined cases of mixing square-hexagonal-hexagonal and square-square-hexagonal OVLs. The particular ordering of the input phase distributions of the OV lattices on the used spatial light modulators is found to affect the orientation of the structures ruled by the hexagonal OVL. Reliable control parameters for the creation of the desired focal beam structures are the respective lattice node spacings. The presented approach is flexible, easily realizable by using a single spatial light modulator, and thus accessible in many laboratories. [ABSTRACT FROM AUTHOR]

Numerical simulations are used to examine the transition dynamics between metastable and ground state vortex lattice phases in a system with combined sixfold and twelvefold contributions to the vortex–vortex interactions. The system is initially annealed using a twelvefold anisotropy, yielding domains of two different orientations and separated by grain boundaries. The vortex–vortex interaction is then suddenly changed to a sixfold anisotropy, rendering the twelvefold state metastable. Applying a drive that mimics an oscillating magnetic field causes the metastable state to decay, indicated by the structure factor that evolves from twelve to six peaks. The results fit the behavior seen in recent small-angle neutron scattering studies of the vortex lattice in MgB _2 . At higher drive amplitudes, the decay exhibits a two step process in which the initial fast decrease is followed by a slower regime where avalanches or bursts are correlated with dislocation annihilation events. The results are compared to other types of metastable systems with quenched disorder that decay under a periodic external drive.

Dynamics of the square optical vortex lattice in broad-area lasers is investigated both numerically and analytically on a base of the full system of Maxwell-Bloch equations. A linear analysis and numerical simulations show the formation of the stationary vortex lattice near the laser threshold. The pump parameter increasing results in the Andronov-Hopf bifurcation and the emergence of vortex lattice oscillations. At further increase of pump parameter, the lattice is destroyed and non-regular moving of separated vortices is observed. Bifurcation diagrams are obtained.

Penetration of a vorticity lattice formed by waves propagating on the surface at an angle to each other into the bulk of a liquid is studied experimentally. It is shown that along with the Stokes drift it is necessary to regard nonlinear wave interaction in order to explain experimental time dependences of average vorticity. Vorticity distribution over the depth of a liquid is described by a sum of two exponents considering the contribution of both mechanisms. It is determined that formation of large-scale vortex flows leads to deformation of a vortex lattice and a decrease in an average value of the amplitude of lattice vorticity as a result of its drift. [ABSTRACT FROM AUTHOR]

High-temperature superconductivity in Fe-based pnictides and chalcogenides has been one of the most significant recent discoveries in condensed matter physics and has attracted remarkable attention in the last decade. These materials are characterized by a complex fermiology and, as a result, feature a wide range of electronic properties as a function of different tuning parameters such as chemical doping, temperature and pressure. Along the path towards the comprehension of the physical mechanisms underlying this rich phenomenology, nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) have played a role of capital importance that we review in this work. In particular, we address how NMR has contributed to the current understanding of the main regions of the electronic phase diagram of Fe-based pnictides, that is, the—sometimes coexisting—antiferromagnetic spin-density wave and superconducting states. We evidence the unique capability of NMR as local-probe technique of investigating the effect of quenched disorder and chemical impurities. Then, we review the NMR signatures of low-frequency fluctuations associated with the development of electronic nematicity as well as with the motion of superconducting flux lines. Finally, we discuss recent contributions of NMR and NQR which evidence an intrinsically inhomogeneous electronic charge distribution as well as an orbitally-selective behaviour. [ABSTRACT FROM AUTHOR]

In this work, we present numerical simulations and experimental evidence for the creation of controllable multi-spot focal arrays composed of bright beams with flat phase profiles. The input phase structures sent to spatial light modulators were square-shaped optical vortex (OV) lattices containing hundreds of vortices. In order to stabilize each of these lattices in space, all used OVs were singly charged and their topological charges varied alternatively across the structures. It is proven that the OV lattice node spacing can be used as a control parameter for reshaping the generated multi-spot focal arrays. Each peak of these arrays is shown to be able to additionally host a singular beam. [ABSTRACT FROM AUTHOR]

This study considers the hydroelastic damping of cantilevered flat plates undergoing free vibration in flowing water. Of particular interest are plates with aspect ratios (defined as span length divided by chord length) less than one. Experimental trials involving plates of aspect ratios from 0.3 to 0.7 are conducted in a high-speed water tunnel. The tests involve flow velocities well below those corresponding to hydroelastic instability. Additionally, an unsteady, linear vortex lattice model is coupled to a structural dynamic plate model to predict flow-induced damping as a function of flow speed. The numerical model has been previously used with air, but never with water as the fluid medium. The model is able to predict the hydroelastic damping associated with the first several plate modes with less than 30% error in most cases. While the hydroelastic damping remains linear in the experimental flow regime, at higher flow speeds more complicated hydroelastic damping behavior is predicted. Numerical studies involving mass ratio, aspect ratio, and reduced velocity are conducted to predict hydroelastic damping across a wide parameter space. All else being equal, chordwise bending modes are found to exhibit two to three times greater hydroelastic damping than spanwise bending modes. There is also an inverse relationship between mass ratio and hydroelastic damping. Further, for plates with low aspect ratios and at fixed reduced velocities, hydroelastic damping increases with increasing aspect ratio. [ABSTRACT FROM AUTHOR]

We report efficient vortex pinning in thickness-modulated tungsten–carbon-based (W–C) nanostructures grown by focused ion beam induced deposition (FIBID). By using FIBID, W–C superconducting films have been created with thickness modulation properties exhibiting periodicity from 60 to 140 nm, leading to a strong pinning potential for the vortex lattice. This produces local minima in the resistivity up to high magnetic fields (2.2 T) in a broad temperature range due to commensurability effects between the pinning potential and the vortex lattice. The results show that the combination of single-step FIBID fabrication of superconducting nanostructures with built-in artificial pinning landscapes and the small intrinsic random pinning potential of this material produces strong periodic pinning potentials, maximizing the opportunities for the investigation of fundamental aspects in vortex science under changing external stimuli (e.g., temperature, magnetic field, electrical current).

We study the information entropy, order, disorder, and complexity for the two-dimensional (2D) rotating and nonrotating Bose-Einstein condensates. The choice of our system is a complete theoretical laboratory where the complexity is controlled by the two-body contact interaction strength and the rotation frequency (Ω) of the harmonic trap. The 2D nonrotating condensate shows the complexity of the category I where the disorder-order transition is triggered by the interaction strength. In the rotating condensates, Ω is chosen as the disorder parameter when the interaction strength is fixed. With respect to Ω, the complexity shifts between maximum and minimum confirm the existence of category II complexity in the rotating condensate. Also, we consider the interaction strength as the disorder parameter when Ω is unchanged and complexity as a function of interaction strength exhibits category III complexity. The present work also includes the calculation of upper bound and lower bound of entropy for 2D quantum systems. [ABSTRACT FROM AUTHOR]