Matter Waves Research Articles

Effect of finite volume on thermodynamics of quark-hadron matter

The effects of a finite system volume on thermodynamic quantities, such as the pressure, energy density, specific heat, speed of sound, conserved charge susceptibilities, and correlations, in hot and dense strongly interacting matter are studied within the parity-doublet chiral mean field model. Such an investigation is motivated by relativistic heavy-ion collisions, which create a blob of hot QCD matter of a finite volume, consisting of strongly interacting hadrons and potentially deconfined quarks and gluons. The effect of the finite volume of the system is incorporated by introducing lower momentum cutoffs in the momentum integrals appearing in the model, the numerical value of the momentum cutoff being related to the de Broglie wavelength of the given particle species. It is found that some of these quantities show a significant volume dependence, in particular, those sensitive to pion degrees of freedom, and the crossover transition is generally observed to become smoother in finite volume. These findings are relevant for the effective equation of state used in fluid dynamical simulations of heavy-ion collisions and efforts to extract the freeze-out properties of heavy-ion collisions with susceptibilities involving electric charge and strangeness. Published by the American Physical Society 2024

Topological atom optics and beyond with knotted quantum wavefunctions

Atom optics demonstrates optical phenomena with coherent matter waves, providing a foundational connection between light and matter. Significant advances in optics have followed the realization of structured light fields hosting complex singularities and topologically non-trivial characteristics. However, analogous studies are still in their infancy in the field of atom optics. Here, we investigate and experimentally create knotted quantum wavefunctions in spinor Bose–Einstein condensates which display non-trivial topologies. In our work we construct coordinated orbital and spin rotations of the atomic wavefunction, engineering a variety of discrete symmetries in the combined spin and orbital degrees of freedom. The structured wavefunctions that we create map to the surface of a torus to form torus knots, Möbius strips, and a twice-linked Solomon’s knot. In this paper we demonstrate close connections between the symmetries and underlying topologies of multicomponent atomic systems and of vector optical fields—a realization of topological atom-optics.

Traveling Wave Solutions of the Conformable Fractional Klein–Gordon Equation With Power Law Nonlinearity

This article investigates the construction of new traveling wave solutions for the conformable fractional Klein–Gordon equation, which is a well‐known mathematical and physical model that can be used to explain spinless pion and de Broglie waves. In order to accomplish this task, a classic and effective analysis method, namely, the extended tanh–coth method, was utilized. By introducing appropriate transformations, the conformable fractional Klein–Gordon equations are reduced to ordinary differential equations, and then the solutions with hyperbolic function form are obtained. In addition, the effect of fractional parameters on waveform is analyzed by drawing two‐ and three‐dimensional graphics. These results contribute to a deeper understanding of the dynamics of the conformable fractional Klein–Gordon equation. The research in this article also indicates that the extended tanh–coth method is a straightforward and concise technique that has the potential to be applicable to many other conformable fractional partial differential equations that appear in mathematical physics.

Wave Particle Duality: De Broglie Waves in Indirect Quantum Measurements

Wave Particle Duality: De Broglie Waves in Indirect Quantum Measurements

QUANTUM PARTICLE OF MATTER (CHARGE) AS A FUNDAMENTAL SOURCE OF GRAVITY AND MASS OF MATTER IN NATURE

One of the most intriguing problems of modern physics is the search of particles beyond the Standard Model and the creation of quantum theory of gravity. To these problems, namely to the problem of quantum description of gravitation the closest attention is paid. The importance of applying the Standard Model to describe three types of force physical interactions involving elementary particles is beyond doubt. These particles are active participants of physical processes of electromagnetism, strong and weak interactions. However, there is still an open question about the meaning and role in nature of gravitation. Moreover, it is not clear how gravity interacts with matter of any mass and what is the essence of these differences. Also, there is no answer to the question about the meaning in the nature of the discreteness factor and the possibility of real quantisation of gravitation. Besides, it is unknown whether in the surrounding world there exists a quantum of gravitational energy – graviton and what is its actual energy. To explain the significance of gravity on cosmic scales, the General Theory of Relativity of A. Einstein was applied, which describes the curvature of space around stars and planets. However, this theory affects only the interaction of large masses of matter and does not apply to quantum objects in the form of atoms and elementary particles. As for the objective application in the scientific literature of other known theories of gravity, including its quantum forms, they all use a mathematical apparatus where the criterion of quantum discreteness – Planck’s constant – is missing. The apparent incompleteness of research in the field of development and creation of an objective theory of gravitation and its quantum forms requires practical application of the existing apparatus of quantum mechanics for realisation of this scientific direction. Taking into account such a view, it is necessary to consider the possibility of applying the thermodynamic nature of the movement of gravity in nature, where it is necessary to raise the issue of the existence and manifestation of the quantum form of gravitational energy in nature, the source of which may be a quantum particle of matter (charge) outside the Standard Model. Due to the unique coincidence of physical properties of quantum particles of matter (charge) and physical principles inherent in the operation of any collider, it is possible to use the Large Hadron Collider to study the properties of quantum particles of matter (charge) as a source of gravity in nature. Keywords: gravity, quantum particle of matter (charge), energy and Planck’s constant, Schrödinger equation, Heisenberg uncertainty, graviton, oscillator of gravity of matter (charge), de Broglie wave, laws of gravity, converging effect of gravitational fields, standard model, collider

Atomic diffraction by nanoholes in hexagonal boron nitride.

Fabricating patterned nanostructures with matter waves can help to realise new nanophotonic devices. However, due to dispersion effects, designing patterns with nanoscale features is challenging. Here, we consider the propagation of a helium matter wave through different holes in hexagonal boron nitride (h-BN) as a case study for the weakest dispersion interaction and the matter wave's diffraction as it passes through the holes. We use a quantum-mechanical model to calculate the polarisability of edge atoms around the holes, where we observe polarisation ripples of enhanced and reduced polarisabilities around the holes. We use these values to calculate van der Waals dispersion coefficients for the scattered helium atoms. We find that the resulting diffraction patterns are affected by the shape and size of the holes, where the smallest holes have a radius of just 6 Å. These results can be used to predict the resolution limits of nano-hole patterns on nanophotonic materials.

High-speed ultrasound imaging of bubbly flows and shear waves in soft matter.

In this methods paper, we explore the capabilities of high-speed ultrasound imaging (USI) to study fast varying and complex multi-phase structures in liquids and soft materials. Specifically, we assess the advantages and the limitations of this imaging technique through three distinct experiments involving rapid dynamics: the underwater flow induced by an external jet, the dissolution of sub-micron bubbles in water, and the propagation of shear waves in a soft elastic material. The phenomena were simultaneously characterized using optical microscopy and USI. In water, we use compounded USI for tracking a multi-phase flow produced by a jetting bubble diving into a liquid pool at speeds around 20 m s-1. These types of jets are produced by focusing a single laser pulse below the liquid surface. Upon breakup, they create a bubbly flow that exhibits high reflectivity to the ultrasound signal, enabling the visualization of the subsequent turbulent flow. In a second experiment, we demonstrate the potential of USI for recording the diffusive shrinkage of micro- and nanobubbles in water that could not be optically resolved. Puncturing an elastic material with a liquid jet creates shear waves that can be utilized for elastography measurements. We analysed the shape and speed of shear waves produced by different types of jetting bubbles in industrial gelatin. The wave characteristics were simultaneously determined by implementing particle velocimetry in optical and ultrasound measurements. For the latter, we employed a novel method to create homogeneously distributed micro- and nanobubbles in gelatin by illuminating it with a collimated laser beam.

Dynamics of Cylindrical Collapse in Palatini Gravity

This research explores how filamentary objects behave when they collapse in the presence of exotic material. To accomplish this, we employ Palatini (R, T) theory as a candidate for exotic material. We derive the collapsing equation by enforcing the Darmois junction condition on the collapsed surface boundary. At this boundary, we obtain that the radial pressure is proportionate to the time‐dependent term of the field and is not zero. Lastly, we investigate the correlation between dark matter and gravitational waves and find that exotic terms disrupt the transmission of gravitational waves. It is worthwhile to mention here that our results (in both formalisms, metric approach and Palatini approach) reduce to (R) gravity and general relativity.

The application of ultraviolet light sources in charge management systems for space gravitational wave detection

Gravitational waves are a type of matter wave generated by the violent motion and changes of matter and energy. Detecting gravitational waves allows humanity to observe the universe from a new perspective. During the process of gravitational wave detection, high-energy particles and cosmic rays in space can penetrate the spacecraft's exterior and reach the surface of the inertial sensor's test mass (TM), causing them to continuously accumulate charge. Once the charge on the TM exceeds a certain threshold, the electrostatic forces between the TM and surrounding conductors generate significant acceleration noise, which adversely affects the measurement accuracy of the inertial sensors and, consequently, the success of the gravitational wave detection mission. Therefore, controlling the charge on the TM surface, known as charge management, is essential. The most commonly used charge management method is based on the photoelectric effect, using ultraviolet (UV) light to control the potential between the surface of the TM and the surrounding conductors. In previous charge management systems (CMS), UV mercury lamps and UV light-emitting diodes (LEDs) have been used as light sources with varying levels of success. This paper primarily reviews the research progress of UV light sources in CMS for space gravitational wave detection. Mercury lamps, as the first-generation system light source, can fulfill the mission but have drawbacks such as slow startup, high power consumption and significant electromagnetic interference. UV LEDs, with their advantages in size and weight, have gradually become the current light source for CMS. In recent years, with advancements in UV micro-LED technology, their higher external quantum efficiency and lower power consumption have demonstrated potential for application in CMS, making them one of the promising UV light sources for future charge management systems.

The exchange effect interference mechanisms in quantum mechanics

In quantum mechanics, there are two interference mechanisms between identical particles. One is that the de Broglie wavelengths of two interference waves are the same, which is called the equal wavelength interference mechanism. There have been many experiments by this mechanism. The other is that the wavelengths of interference waves can also be different, in which case there should be an exchange term in addition to the direct term in the wave function. There is a fixed phase difference between the two terms, which causes interference. This is called exchange effect interference mechanism. There is a special case where two interference waves can satisfy both the two mechanisms. We propose an experiment to discriminate that in this case which mechanism plays a role on earth. By the exchange effect interference mechanism, it is possible to construct artificial crystals and to study the physical properties of this kind of crystals.

Dark Matter Waves, Particles, Nuggets, and Other Paradigms

Dark Matter Waves, Particles, Nuggets, and Other Paradigms

Quantum mechanical lateral force on an atom due to matter wave

The area of trapping the atoms or molecules using light has advanced tremendously in the last few decades. In contrast, the idea of controlling (not only trapping) the movement of atomic-sized particles using matter waves is a completely new emerging area of particle manipulation. Though a single previous report has suggested the pulling of atoms based on matter-wave tractor beams, an attempt is yet to be made to produce a lateral force using this technique. This article demonstrates an asymmetric setup that engenders reversible lateral force on an atom due to the interaction energy of the matter wave in the presence of a metal surface. Several full-wave simulations and analytical calculations were performed on a particular set-up of Xenon scatterers placed near a Copper surface, with two counter-propagating plane matter waves of Helium impinging in the direction parallel to the surface. By solving the time-independent Schrödinger equation and using the solution, quantum mechanical stress tensor formalism is applied to compute the force acting on the particle. The simulation results are in excellent agreement with the analytical calculations. The results for the adsorbed scatterer case find this technique to be an efficient cleaning procedure similar to electron-stimulated desorption for futuristic applications.

A generic formation mechanism of ultralight dark matter solar halos

As-yet undiscovered light bosons may constitute all or part of the dark matter (DM) of our Universe, and are expected to have (weak) self-interactions. We show that the quartic self-interactions generically induce the capture of dark matter from the surrounding halo by external gravitational potentials such as those of stars, including the Sun. This leads to the subsequent formation of dark matter bound states supported by such external potentials, resembling gravitational atoms (e.g. a solar halo around our own Sun). Their growth is governed by the ratio ξ foc ≡ λdB/R ⋆ between the de Broglie wavelength of the incoming DM waves, λdB, and the radius of the ground state R ⋆.For ξ foc ≲ 1, the gravitational atom grows to an (underdense) steady state that balances the capture of particles and the inverse (stripping) process. For ξ foc ≳ 1, a significant gravitational-focusing effect leads to exponential accumulation of mass from the galactic DM halo into the gravitational atom. For instance, a dark matter axion with mass of the order of 10-14 eV and decay constant between 107 and 108 GeV would form a dense halo around the Sun on a timescale comparable to the lifetime of the Solar System, leading to a local DM density at the position of the Earth 𝒪(104) times larger than that expected in the standard halo model. For attractive self-interactions, after its formation, the gravitational atom is destabilized at a large density, which leads to its collapse; this is likely to be accompanied by emission of relativistic bosons (a `Bosenova').

Paraxial Dirac equation

In this work, the paraxial approximation of the free Dirac equation is examined. The results are first obtained by constructing superpositions of exact solutions with suitable profiles, which are borrowed from paraxial optics. In this manner, the paraxial Dirac beams are obtained in four cases: as Gaussian, Bessel-Gaussian, modified Bessel-Gaussian and elegant Laguerre-Gaussian beams. In the second part of the work, the paraxial Dirac equation is derived, and then its solutions in the aforementioned cases are directly obtained. All the resulting wave functions conform to those derived formerly by virtue of superpositions, except for terms that are negligible upon the assumption that the paraxial functions along the propagation axis vary only slightly over a distance equal to the de Broglie wavelength, which is the standard paraxial requirement.

Stability analysis of nonlinear localized modes in the coupled Gross-Pitaevskii equations with [Formula: see text] -symmetric Scarf-II potential.

We study the nonlinear localized modes in two-component Bose-Einstein condensates with parity-time-symmetric Scarf-II potential, which can be described by the coupled Gross-Pitaevskii equations. Firstly, we investigate the linear stability of the nonlinear modes in the focusing and defocusing cases, and get the stable and unstable domains of nonlinear localized modes. Then we validate the results by evolving them with 5% perturbations as an initial condition. Finally, we get stable solitons by considering excitations of the soliton via adiabatical change of system parameters. These findings of nonlinear modes can be potentially applied to physical experiments of matter waves in Bose-Einstein condensates.

Dynamical self-trapping of two-dimensional binary solitons in cross-combined linear and nonlinear optical lattices.

Dynamical and self-trapping properties of two-dimensional (2D) binary mixtures of Bose-Einstein condensates in cross-combined lattices, consisting of a one-dimensional (1D) linear optical lattice (LOL) in the x direction for the first component and a 1D nonlinear optical lattice (NOL) in the y direction for the second component, are analytically and numerically investigated. The existence and stability of 2D binary matter wave solitons in these settings are demonstrated both by variational analysis and by direct numerical integration of the coupled Gross-Pitaevskii equations. We find that in the absence of the NOL, binary solitons, stabilized by the action of the 1D LOL and by the attractive intercomponent interaction, can freely move in the y direction. In the presence of the NOL, we find, quite remarkably, the existence of threshold curves in the parameter space separating regions where solitons can move from regions where the solitons become dynamically self-trapped. The mechanism underlying the dynamical self-trapping phenomenon (DSTP) is qualitatively understood in terms of a dynamical barrier induced by the NOL, similar to the Peirls-Nabarro barrier of solitons in discrete lattices. DSTP is numerically demonstrated for binary solitons that are put in motion both by phase imprinting and by the action of external potentials applied in the y direction. In the latter case, we show that the trapping action of the NOL allows one to maintain a 2D binary soliton at rest in a nonequilibrium position of a parabolic trap or to prevent it from falling under the action of gravity. Possible applications of the results are also briefly discussed.

Riding the dark matter wave: Novel limits on general dark photons from LISA Pathfinder

We note the possibility to perform a parametrically improved search for gauged baryon (B) and baryon minus lepton (B−L) Dark Photon Dark Matter (DPDM) using auxiliary channel data from LISA Pathfinder. In particular we use the measurement of the differential movement between the test masses (TMs) and the space craft (SC) which is nearly as sensitive as the tracking between the two TMs. TMs and SC are made from different materials and therefore have different charge-to-mass ratios for both B−L and B. Thus, the surrounding DPDM field induces a relative acceleration of nearly constant frequency. For the case of B−L, we find that LISA Pathfinder can constrain previously unexplored parameter space, providing the world leading limits in the mass range 4⋅10−19eV<m<3⋅10−17eV. This limit can easily be recast also for dark photons that arise from gauging other global symmetries of the SM.

Study on the Diffraction-like and Interference-like Mechanisms of Particle Flow

This paper demonstrates that the light and dark fringe in Young&amp;#39;s double-slit experiment is not actually the diffraction and interference pattern of light wave. We investigate the scattering phenomenon after the particle flow passes through the gaps and find that the scattering type and scattering degrees of freedom of the particle flow depend on the physical parameters of the particles and the gaps. When the particle flow undergoes uniform scattering, a uniform &amp;quot;yes&amp;quot; and &amp;quot;no&amp;quot; interspersed discrete distribution pattern will form on the receiving screen. Based on the diffraction-like and interference-like mechanism of particle flow, this paper explains the electron diffraction and interference experiment, as well as the Young&amp;#39;s double-slit interference experiment and the diffraction of light through circular holes and plates. This article provides an in-depth discussion on Einstein&amp;#39;s concept of wave particle duality and de Broglie&amp;#39;s matter wave hypothesis, as well as an analysis of Feynman&amp;#39;s experimental idea of electron double slit interference. Our research shows that the matter wave hypothesis is not valid, which has shaken the foundation of modern quantum mechanics and has significant scientific significance. In addition, this study has important application value for the development of technology for detecting and analyzing particles or gaps.

Investigating the atomic behavior of carbon nanotubes as nanopumps

In this study, we utilized molecular dynamics (MD) simulations to investigate the nano pumping process of Carbon Nanotube (CNT) in an aqueous environment. In this research, an attempt has been made to investigate and analyze the pumping process of fullerene C20 and water molecules through a carbon nanotube that is externally stimulated by two oscillators. It should be noted that this nano pump is completely immersed in an aqueous environment and the inside and outside of the carbon nanotube is filled with water molecules. To simulate the aqueous environment with NaCl impurities and carbon structures, we employed the Universal Force Field and Tersoff interatomic potentials, respectively. The stability of the simulated structures was demonstrated through an equilibrium process, which was a result of the appropriate settings in our MD simulations. To describe the CNT nano pumping process, we analyzed the velocity and translational/rotational components of C20 kinetic energy over time steps. By decreasing the water impurity concentration from 0.50 to 0.075 mol/l, the nano pumping time varied from 10.98 to 10.11 ps, respectively. Additionally, optimization of the atomic wave producing in the nano pumping process led to a further decrease in pumping time to 10.01 ps. Finally, a 2.86% variation in calculated results was observed by changing the water MD simulation model from SPC to TIP4P.

Structured matter wave evolution in external time-dependent fields

Structured matter wave evolution in external time-dependent fields