Casimir Effect

We introduce phenomenological understanding of the electromagnetic component of the physical vacuum, the EM vacuum, as a basic medium for all masses of the expanding Universe, and "Casimir polarization" of this medium arising in the vicinity of any material object in the Universe as a result of conjugation of the electric field components of the EM vacuum on both sides ("external" and "internal") of atomic nucleus boundary of the each mass with vacuum. It is shown that the gravitational attraction of two material objects in accordance with Newton's law of gravity arises as a result of overlapping of the domains of Casimir polarization of the EM vacuum created by atomic nuclei of the objects, taking into account the longrange gravitational influence of all masses of the Universe on each nucleus of these objects (Mach's idea). Newton's law of gravitational attraction between two bodies is generalized to the case of gravitational interaction of a system of bodies when the center of mass of the pair of bodies shifted relative to the center of mass of the system. The unique smallness of gravitational interactions as compared with the fundamental nuclear (strong and weak) and electromagnetic ones is determined by the ratio of the characteristic size of the domain of Casimir polarization of the EM vacuum in the vicinity of atomic nuclei to the Hubble radius of the Universe.

The present paper-a continuation of our recent series of papers on Casimir friction for a pair of particles at low relative particle velocity-extends the analysis, so as to include dense media. The situation becomes, in this case, more complex, due to induced dipolar correlations, both within planes and between planes. We show that the structure of the problem can be simplified by regarding the two half-planes as a generalized version of a pair of particles. It turns out that macroscopic parameters, such as permittivity, suffice to describe the friction, also in the finite density case. The expression for the friction force per unit surface area becomes mathematically well-defined and finite at finite temperature. We give numerical estimates and compare them with those obtained earlier by Pendry (1997) and by Volokitin and Persson (2007). We also show in an appendix how the statistical methods that we are using correspond to the field theoretical methods more commonly in use.

Following on from our previous study of the geodesic flow on three dimensional ellipsoid with equal middle semi-axes, here we study the remaining cases: Ellipsoids with two sets of equal semi-axes with SO(2) × SO(2) symmetry, ellipsoids with equal larger or smaller semi-axes with SO(2) symmetry, and ellipsoids with three semi-axes coinciding with SO(3) symmetry. All of these cases are Liouvilleintegrable, and reduction of the symmetry leads to singular reduced systems on lower-dimensional ellipsoids. The critical values of the energy-momentum maps and their singular fibers are completely classified. In the cases with SO(2) symmetry there are corank 1 degenerate critical points; all other critical points are non-degenreate. We show that in the case with SO(2) × SO(2) symmetry three global action variables exist and the image of the energy surface under the energymomentum map is a convex polyhedron. The case with SO(3) symmetry is noncommutatively integrable, and we show that the fibers over regular points of the energy-casimir map are T 2 bundles over S 2 .

We revisit the problem of the Casimir force between high-Tc superconductors below and above the critical temperature for the superconducting transition. Ceramic superconductors exhibit a different temperature dependence of the reflectivity when switching from the normal to the superconducting state. We leverage this unique characteristic with respect to ordinary metals to claim that these kind of materials can prove useful as an alternative system where the long-standing discussion on the role of electronic relaxation can be addressed. Furthermore, we show that the two main damping mechanisms associated with free and mid-infrared electrons dominate at very distinct scales, meaning that they can be considered separately when the Casimir force is measured as a function of slab distance. This facilitates the experimental identification of the role of the two electronic relaxation contributions to the force.

ABSTRACTWe present a theoretical study of vacuum effects in systems of length scales of micrometers and nanometers. In particular, we calculate the Casimir force between dielectric plates with different compositions. We show that by an appropriate choice and configurations of materials, the Casimir forces develop noticeable changes than could be used to inhibit or modulate the action of vacuum fluctuations in MEMS and NEMS.

We investigated here the influence of the lateral and normal Casimir force on the actuation dynamics between sinusoidal corrugated surfaces undergoing both normal and lateral displacements. The calculations were performed for topological insulators and phase change materials that are of high interest for device applications. The results show that the lateral Casimir force becomes stronger by increasing the material conductivity and the corrugations toward similar sizes producing wider normal separation changes during lateral motion. In a conservative system, bifurcation and Poincaré portrait analysis shows that larger but similar in size corrugations and/or higher material conductivity favor stable motion along the lateral direction. However, in the normal direction, the system shows higher sensitivity on the optical properties for similar in size corrugations leading to reduced stable operation for higher material conductivity. Furthermore, in non-conservative systems, the Melnikov function with the Poincaré portrait analysis was combined to probe the possible occurrence of chaotic motion. During lateral actuation, systems with more conductive materials and/or the same but high corrugations exhibit lower possibility for chaotic motion. By contrast, during normal motion, chaotic behavior leading to stiction of the moving components is more likely to occur for systems with more conductive materials and similar in magnitude corrugations.

We investigated here the influence of the lateral Casimir force on the dynamical actuation of devices with interacting materials covering a broad range of optical properties ranging from poor to good conductors, such as, for example, nitrogen doped SiC and Au, respectively. The conservative actuating system shows a central heteroclinic orbit surrounded by a finite number of homoclinic orbits, because at higher periods, an increased lateral Casimir force will be necessary to counterbalance the restoring force. As a result, the conservative system reaches stable operation sooner for the higher conductivity materials (Au-Au), indicating the significant impact of the material optical properties on the lateral Casimir force. Furthermore, for the non-conservative driven systems, the decrement of the Melnikov parameter α leads to a faster disappearance of the satellite homoclinic orbits in the Poincaré portraits, followed by a strong shrinkage of the central heteroclinic orbit toward unstable chaotic motion. The latter is more pronounced for the lower conductivity materials since comparison shows the Au-Au system to be significantly more stable than the SiC-SiC system. Therefore, in actuating systems where the lateral Casimir force could play a significant role, the higher conductivity materials appear to be a better choice to ensure stable operation against a chaotic motion.

The sensitivity of nonequilibrium Casimir forces on material optical properties can have strong impact on the actuation of devices. For this purpose, we considered nonequilibrium Casimir interactions between good and poor conductors, for example, gold (Au) and highly doped silicon carbide (SiC), respectively. Indeed, for autonomous conservative systems, the bifurcation and phase portrait analysis have shown that the nonequilibrium Casimir forces can have signi cant impact on the stable and unstable operating regimes depending on the material optical properties. At a few micrometer separations, for systems with high conductivity materials, an increasing temperature di erence between the actuating components can enhance the stable operation range due to the reduction of the Casimir force, while for the poor conductive materials, the opposite takes place. For periodically driven dissipative systems, the Melnikov function and Poincare portrait analysis have shown that for poor conductive systems, the nonequilibrium Casimir forces lead to an increased possibility for chaotic behavior and stiction with an increasing temperature di erence between the actuating components. However, for good conducting systems, the thermal contribution to Casimir forces reduces the possibility for chaotic behavior with increasing temperature, as comparison with systems without thermal uctuations shows. Nevertheless, the positive bene t of good conductors toward increased actuation stability and reduced the chaotic behavior under nonequilibrium conditions can be easily compromised by any voltage application. Therefore, thermal, nonequilibrium Casimir forces can in uence the actuation of devices toward unstable and chaotic behavior in strong correlation with their optical properties, and associated conduction state, as well as applied electrostatic potentials.

With Casimir and electrostatic forces playing a crucial role for the performance and stability of microelectromechanical systems (MEMS), the presence of chaotic behavior, which is often unavoidable, leads to device malfunction due to stiction. Therefore, we investigate here how the optical properties of different materials influence the chaotic behavior of electrostatic torsional MEMS due to changes in magnitude of the Casimir forces and torques. We consider the materials Au, which is a good conductor, AIST, which is a phase change material being close to metal in the crystalline state, and finally doped SiC as a very poor conductor. For the conservative systems, there is no chaotic behavior and the analysis of phase portraits and bifurcation diagrams reveal the strong sensitivity of stable actuation dynamics on the material optical properties, while applied electrostatic potentials lead faster to instability and stiction for higher conductivity materials. For the driven systems, the Melnikov method is used to study the chaotic behavior. The results from this method are supported by the study of the contours of the transient time to stiction in the phase plane, which reveal a substantially increased chaotic behavior for higher conductivity materials, associated with stronger Casimir torques and applied electrostatic potentials.

In the current study, we explore the sensitivity of the actuation dynamics of electromechanical systems on novel materials, e.g., Bi2Se3, which is a well-known 3D Topological Insulator (TI), and compare their response to metallic conductors, e.g., Au, that are currently used in devices. Bifurcation and phase portraits analysis in conservative systems suggest that the strong difference between the conduction states of Bi2Se3 and Au yields sufficiently weaker Casimir force to enhance stable operation. Furthermore, for nonconservative driven systems, the Melnikov function and Poincare portrait analysis probed the occurrence of chaotic behavior leading to increased risk for stiction. It was found that the presence of the TI enhanced stable operation against chaotic behavior over a significantly wider range of operation conditions in comparison to typical metallic conductors. Therefore, the use of TIs can allow sufficient surface conductance to apply electrostatic compensation of residua...

We investigated here the influence of the lateral and normal Casimir force on the actuation dynamics between sinusoidal corrugated surfaces undergoing both normal and lateral displacements. The calculations were performed for topological insulators and phase change materials that are of high interest for device applications. The results show that the lateral Casimir force becomes stronger by increasing the material conductivity and the corrugations toward similar sizes producing wider normal separation changes during lateral motion. In a conservative system, bifurcation and Poincaré portrait analysis shows that larger but similar in size corrugations and/or higher material conductivity favor stable motion along the lateral direction. However, in the normal direction, the system shows higher sensitivity on the optical properties for similar in size corrugations leading to reduced stable operation for higher material conductivity. Furthermore, in non-conservative systems, the Melnikov...

Here, we investigate the sensitivity of nonequilibrium Casimir forces to optical properties at low frequencies via the Drude and plasma models and the associated effects on the actuation of microelectromechanical systems. The stability and chaotic motion for both autonomous conservative and nonconservative driven systems were explored assuming good, e.g., Au, and poor, e.g., doped SiC, interacting conductors having large static conductivity differences. For both material systems, we used the Drude and plasma methods to model the optical properties at low frequencies, where measurements are not feasible. In fact, for the conservative actuating system, bifurcation and phase space analysis show that the system motion is strongly influenced by the thermal nonequilibrium effects depending on the modeling of the optical properties at low frequencies, where also the presence of residual electrostatic forces can also drastically alter the actuating state of the system, depending strongly on...

We investigate the influence of Casimir and electrostatic torques on double beam torsional microelectromechanical systems with materials covering a broad range of conductivities of more than three orders of magnitude. For the frictionless autonomous systems, bifurcation and phase space analysis shows that there is a significant difference between stable and unstable operating regimes for equal and unequal applied voltages on both sides of the double torsional system giving rise to heteroclinic and homoclinic orbits, respectively. For equal applied voltages, only the position of a symmetric unstable saddle equilibrium point is dependent on the material optical properties and electrostatic effects, while in any other case there are stable and unstable equilibrium points are dependent on both factors. For the periodically driven system, a Melnikov 2 function approach is used to show the presence of chaotic motion rendering predictions of whether stiction or stable actuation will take place over long times impossible. Chaotic behavior introduces significant risk for stiction, and it is more prominent to occur for the more conductive systems that experience stronger Casimir forces and torques. Indeed, when unequal voltages are applied, the sensitive dependence of chaotic motion on electrostatics is more pronounced for the highest conductivity systems.

Here, we investigate the dynamical sensitivity of electrostatic torsional type microelectromechanical systems (MEMS) on the optical properties of interacting materials. This is accomplished by considering the combined effect of mechanical Casimir and electrostatic torques to drive the device actuation. The bifurcation curves and the phase portraits of the actuation dynamics have been analyzed to compare the sensitivity of a single beam torsional device operating between materials with conductivities that differ by several orders of magnitude. It is shown that the range of stable operation of torsional MEMS against stiction instabilities can increase by decreasing the conductivity of interacting materials. Moreover, the introduction of controlled dissipation, corresponding to a finite quality factor, in an otherwise unstable torsional system, could alter an unstable motion towards stiction to dissipative stable motion.

We have investigated the dynamical actuation of micro-electromechanical systems under the influence of attractive and repulsive Casimir forces between topological insulator plates as a function of their dielectric function and coating magnetization. The analysis of the Casimir force in the limit of strong and weak magnetization shows that the attractive force, which is produced for plate magnetizations in the same direction, is greater than the repulsive force that is produced for opposite magnetizations. However, both forces remain comparable for intermediate magnetizations. Moreover, for weak magnetization, the attractive force becomes stronger for an increasing dielectric function, while the opposite occurs for the repulsive force. On the other hand, increasing magnetization decreases the influence of the dielectric function on both the repulsive and attractive forces. Furthermore, for conservative systems, bifurcation and phase portrait analysis revealed that increasing magnetiz...

We examine the lowest order quantum corrections to the effective action arising from a quantized real scalar field in the Randall-Sundrum background spacetime. The leading term is the familiar vacuum, or Casimir, energy density. The next term represents an induced gravity term that can renormalize the 4-dimensional Newtonian gravitational constant. The calculations are performed for an arbitrary spacetime dimension. Two inequivalent boundary conditions, corresponding to twisted and untwisted field configurations, are considered. A careful discussion of the regularization and renormalization of the effective action is given, with the relevant counterterms found. It is shown that the requirement of self-consistency of the Randall-Sundrum solution is not simply a matter of minimizing the Casimir energy density. The massless, conformally coupled scalar field results are obtained as a special limiting case of our results. We clarify a number of differences with previous work.

We study the contribution of the thermal zero modes to the Casimir free energy, in the case of a fluctuating electromagnetic (EM) field in the presence of real materials described by frequencydependent, local and isotropic permittivity () and permeability (µ) functions. Those zero modes, present at any finite temperature, become dominant at high temperatures, since the theory is dimensionally reduced. Our work, within the context of the Derivative Expansion (DE) approach, focusses on the emergence of non analyticities in that dimensionally reduced theory. We conclude that the DE is well defined whenever the function Ω(ω), defined by [Ω(ω)] 2 ≡ ω 2 (ω), vanishes in the zero-frequency limit, for at least one of the two material media involved.

We study the long-range interaction between two hydrogen atoms, in both the van der Waals and Casimir-Polder regimes. The retardation regime is reached when the finiteness of the speed of light becomes relevant. Provided that both atoms are in the ground states, the retardation regime is achieved when the interatomic distance, R, is larger than 137 a 0 , where a 0 is the Bohr radius. v

We evaluate two integrals over x ∈ [0,1] involving products of the function ζ 1 (a,x) ≡ ζ (a,x) − x −a for ℜ(a) > 1 , where ζ (a,x) is the Hurwitz zeta function. The evaluation of these integrals for the particular case of integer a 2 is also presented. As an application we calculate the O(g) weak-coupling expansion coefficient c 1 (ε) of the Casimir energy for a film with Dirichlet-Dirichlet boundary conditions, first stated by Symanzik [Schrödinger representation and Casimir effect in renormalizable quantum field theory, Nucl. Phys. B 190 (1981) 1-44] in the framework of gφ 4 4−ε theory.

The Casimir 1 force between two ideal conducting surfaces is a special (zero temperature) limit of a more general theory due to Lifshitz 2. Extensions of this theory of van der Waals forces between dielectric plates to include an intermediate medium were derived from quantum field theory by Dzyaloshinski et al 3. The mystique that

In this article, we analyse some unspecific details which are significant in certain experiment related to Casimir effect. At the "point of closest approach", as the Casimir force equals the Coulombic force, we can calculate the static energy density. Also, identical phenomena occurs in the cosmological H and HeI Rydberg atoms. In spite of the marked contrast between both scales, by extrapolation, utilizing a dynamical expression for this microscopic magnitudes, we can obtain the Cosmological Constant. Due to its intensives form, these finding are fascinating, since from a specific microscopic empty cavity, we can equalize its expansive energy density with respect to the cosmological energy density.

Centrum voor Wiskunde en Informatica (CWI) is the national research institute for Mathematics and Computer Science. It is sponsored by the Netherlands Organisation for Scientific Research (NWO). CWI is a founding member of ERCIM, the European Research Consortium for Informatics and Mathematics. CWI's research has a theme-oriented structure and is grouped into four clusters. Listed below are the names of the clusters and in parentheses their acronyms. Probability, Networks and Algorithms (PNA) Software Engineering (SEN) Modelling, Analysis and Simulation (MAS) Information Systems (INS)

We investigate the Casimir effect of a rough membrane within the framework of the Hořava-Lifshitz theory in 2+1 dimensions. Quantum fluctuations are induced by an anisotropic scalar field subject to Dirichlet boundary conditions. We implement a coordinate transformation to render the membrane completely flat, treating the remaining terms associated with roughness as a potential. The spectrum is obtained through perturbation theory and regularized using the ζ-function method. We present an explicit example of a membrane with periodic border. Additionally, we consider the effect of temperature. Our findings reveal that the Casimir energy and force depend on roughness, the anisotropic scaling factor and temperature.

In this paper, we present a control-design method based on the energy-Casimir method for infinite-dimensional, boundary-actuated port-Hamiltonian systems with two-dimensional spatial domain and second-order Hamiltonian. The resulting control law depends on distributed system states that cannot be measured, and therefore, we additionally design an infinitedimensional observer by exploiting the port-Hamiltonian system representation. A Kirchhoff-Love plate serves as an example in order to demonstrate the proposed approaches.

In this paper, we consider nonlinear PDEs in a port-Hamiltonian setting based on an underlying jet-bundle structure. We restrict ourselves to systems with 1-dimensional spatial domain and 2nd-order Hamiltonian including certain dissipation models that can be incorporated in the port-Hamiltonian framework by means of appropriate differential operators. For this system class, energy-based control by means of Casimir functionals as well as energy balancing is analysed and demonstrated using a nonlinear Euler-Bernoulli beam.

In this paper, we consider infinite-dimensional port-Hamiltonian systems with indomain actuation by means of an approach based on Stokes-Dirac structures as well as in a framework that exploits an underlying jet-bundle structure. In both frameworks, a dynamic controller based on the energy-Casimir method is derived in order to stabilise certain equilibrias. Moreover, we propose distributed-parameter observers deduced by exploiting damping injection for the observer error. Finally, we compare the approaches by means of an in-domain actuated vibrating string and show the equivalence of the control schemes derived in both frameworks.

In this paper, we consider nonlinear PDEs in a port-Hamiltonian setting based on an underlying jet-bundle structure. We restrict ourselves to systems with 1-dimensional spatial domain and 2nd-order Hamiltonian including certain dissipation models that can be incorporated in the port-Hamiltonian framework by means of appropriate differential operators. For this system class, energy-based control by means of Casimir functionals as well as energy balancing is analysed and demonstrated using a nonlinear Euler-Bernoulli beam.

We explore the statistical properties of the Casimir-Polder potential between a dielectric sphere and a three-dimensional heterogeneous medium, by means of extensive numerical simulations based on the scattering theory of Casimir forces. The simulations allow us to confirm recent predictions for the mean and standard deviation of the Casimir potential, and give us access to its full distribution function in the limit of a dilute distribution of heterogeneities. These predictions are compared with a simple statistical model based on a pairwise summation of the individual contributions of the constituting elements of the medium.

We study the quantum reflection of ultracold antihydrogen atoms bouncing on the surface of a liquid helium film. The Casimir-Polder potential and quantum reflection are calculated for different thicknesses of the film supported by different substrates. Antihydrogen can be protected from annihilation for as long as 1.3s on a bulk of liquid 4 He, and 1.7s for liquid 3 He. These large lifetimes open interesting perspectives for spectroscopic measurements of the free fall acceleration of antihydrogen. Variation of the scattering length with the thickness of a film of helium shows interferences which we interpret through a Liouville transformation of the quantum reflection problem.

An ultracold atom above a horizontal mirror experiences quantum reflection from the attractive Casimir-Polder interaction, which holds it against gravity and leads to quantum levitation states. We analyze this system by using a Liouville transformation of the Schrödinger equation and a Langer coordinate adapted to problems with a classical turning point. Reflection on the Casimir-Polder attractive well is replaced by reflection on a repulsive wall and the problem is then viewed as an ultracold atom trapped inside a cavity with gravity and Casimir-Polder potentials acting respectively as top and bottom mirrors. We calculate numerically Casimir-Polder shifts of the energies of the cavity resonances and propose a new approximate treatment which is precise enough to discuss spectroscopy experiments aiming at tests of the weak equivalence principle on antihydrogen. We also discuss the lifetimes by calculating complex energies associated with cavity resonances.

The GBAR experiment will time the free fall of cold antihydrogen atoms dropped onto an annihilation plate to test the universality of free fall on antimatter. In this contribution, we study the quantum reflection of the anti-atom resulting from the Casimir-Polder attraction to the plate. We evaluate the Casimir-Polder potential and the associated quantum reflection amplitudes and find that reflection is enhanced for weaker potentials. A Liouville transformation of the Schrödinger equation is used to map the quantum reflection problem onto an equivalent problem of scattering on a barrier, leading to an intuitive understanding of the phenomenon.

We study universal Casimir interactions in two configurations which appear as dual to each other. The first involves spheres described by the Drude model and separated by vacuum while the second involves dielectric spheres immersed in a salted solution at distances larger than the Debye screening length. In both cases, the long-distance limit, equivalently the high-temperature limit, is dominated by the effect of low-frequency transverse magnetic thermal fluctuations. They are independent of the details of dielectric functions of materials, due to the finite conductivity of metals in the former case and of salted water in the latter one. They also show universality properties in their dependence on geometric dimensions, in relation to an approximate conformal invariance of the reduced free energy. A. High-temperature limit Within the scattering approach [25], the Casimir free energy at a temperature T is given as a sum over the imaginary Matsubara frequencies [26, 27] F = k B T 2 ∞ n=−∞ tr log (1 − M(|ξ n |)) , ξ n = 2πnk B T .

In order to compare recent experimental results with theoretical predictions we study the influence of finite conductivity of metals on the Casimir effect. The correction to the Casimir force and energy due to imperfect reflection and finite temperature are evaluated for plane metallic plates where the dielectric functions of the metals are modeled by a plasma model. The results are compared with the common approximation where conductivity and thermal corrections are evaluated separately and simply multiplied.

It has been increasingly becoming clear that Casimir and Casimir‐Polder entropies may be negative in certain regions of temperature and separation. In fact, the occurrence of negative entropy seems to be a nearly ubiquitous phenomenon. This is most highlighted in the quantum vacuum interaction of a nanoparticle with a conducting plate or between two nanoparticles. It has been argued that this phenomenon does not violate physical intuition, since the total entropy, including the self‐entropies of the plate and the nanoparticle, should be positive. New calculations, in fact, seem to bear this out at least in certain cases.

We examine the conditions of validity for the Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic plane mirrors. As in the previously studied case of non-magnetic materials (Guérout et al, Phys. Rev. E 90 042125), we recover the usual expression for the lossy model of optical response, but not for the lossless plasma model. We also show that the modes associated with the Foucault currents play a crucial role in the limit of vanishing losses, in contrast to expectations.

Liouville transformations map in a rigorous manner one Schrödinger equation into another, with a changed scattering potential. They are used here to transform quantum reflection of an atom on an attractive well into reflection of the atom on a repulsive wall. While the scattering properties are preserved, the corresponding semiclassical descriptions are completely different. A quantitative evaluation of quantum reflection probabilities is deduced from this method.

Negative values of the Casimir entropy occur quite frequently at low temperatures in arrangements of metallic objects. The physical reason lies either in the dissipative nature of the metals as is the case for the plane-plane geometry or in the geometric form of the objects involved. Examples for the latter are the sphere-plane and the sphere-sphere geometry, where negative Casimir entropies can occur already for perfect metal objects. After appropriately scaling out the size of the objects, negative Casimir entropies of geometric origin are particularly pronounced in the limit of large distances between the objects. We analyze this limit in terms of the different scattering channels and demonstrate how the negativity of the Casimir entropy is related to the polarization mixing arising in the scattering process. If all involved objects have a finite zero-frequency conductivity, the channels involving transverse electric modes are suppressed and the Casimir entropy within the large-d...

Kelvin probe force microscopy at normal pressure was performed by two different groups on the same Au-coated planar sample used to measure the Casimir interaction in a sphere-plane geometry. The obtained voltage distribution was used to calculate the separation dependence of the electrostatic pressure Pres(D) in the configuration of the Casimir experiments. In the calculation it was assumed that the potential distribution in the sphere has the same statistical properties as the measured one, and that there are no correlation effects on the potential distributions due to the presence of the other surface. The result of this calculation, using the currently available knowledge, is that Pres(D) does not explain the magnitude or the separation dependence of the difference ∆P (D) between the measured Casimir pressure and the one calculated using a Drude model for the electromagnetic response of Au. We discuss in the conclusions the points which have to be checked out by future work, including the influence of pressure and a more accurate determination of the patch distribution, in order to confirm these results.

Disordered geometrical boundaries such as rough surfaces induce important modifications to the mode spectrum of the electromagnetic quantum vacuum. In analogy to Anderson localization of waves induced by a random potential, here we show that the Casimir-Polder interaction between a cold atomic sample and a rough surface also produces localization phenomena. These effects, that represent a macroscopic manifestation of disorder in quantum vacuum, should be observable with Bose-Einstein condensates expanding in proximity of rough surfaces.

We study theoretically interference of the long-living quasistationary quantum states of antihydrogen atoms, localized near a concave material surface. Such states are an antimatter analog of the whispering gallery states of neutrons and matter atoms, and similar to the whispering gallery modes of sound and electromagnetic waves. Quantum states of antihydrogen are formed by the combined effect of quantum reflection from van der Waals/Casimir-Polder (vdW/CP) potential of the surface and the centrifugal potential. We point out a method for precision studies of quantum reflection of antiatoms from vdW/CP potential; this method uses interference of the whispering gallery states of antihydrogen.

We study quantum reflection of antihydrogen atoms from nanoporous media due to the Casimir-Polder (CP) potential. Using a simple effective medium model, we show a dramatic increase of the probability of quantum reflection of antihydrogen atoms if the porosity of the medium increases. We discuss the limiting case of reflections at small energies, which have interesting applications for trapping and guiding antihydrogen using material walls.

Physical adsorption of atoms, molecules and clusters on surface is well known. It is linked to many other phenomena in physics, chemistry, biology, and has numerous practical applications. Due to limitations of analytical tools usually used, studies of adsorption are limited to the particle sizes of up to ~10 2-10 3 atoms. Following a general formalism developed in this field we apply it to even larger objects and discover qualitatively new phenomena. A large particle is bound to surface in a deep and broad potential well formed by van der Waals/ Casimir-Polder forces (vdW/CP) appearing due to the particle and surface electric polarization. The well depth is significantly larger than the characteristic energy of a particle thermal motion; thus such a nanoparticle is settled in long-living states. Nanoparticles in high-excited states form two-dimensional gas of objects bound to surface but quasi-freely traveling along surface at certain conditions. A particularly interesting feature of this model consists in prediction of small-energy-transfer inelastic scattering of ultracold neutrons (UCN) on solid/ liquid surfaces covered by such levitating nanoparticles/ nano-droplets. The change in UCN energy is due to the Doppler shift induced by UCN collisions with nanoparticles/ nano-droplets; the energy change is about as small as the UCN initial energy. We compare theoretical estimations of our model to all existing data on inelastic scattering of UCN with small energy transfers and state that they agree quite well. As our theoretical formalism provides robust predictions of some data and the experimental data are rather detailed and precise, we conclude that the recently discovered intriguing phenomenon of small heating of UCN in traps is due to their collisions with such levitating nanoparticles. Moreover, this new phenomenon might be relevant to the striking contradiction between results of the neutron lifetime measurements with smallest reported uncertainties as it might cause major false effects in these experiments; thus it affects fundamental conclusions concerning precision checks of unitarity of the Cabibbo-Kobayashi-Maskawa matrix, cosmology, astrophysics. Dedicated measurements of UCN inelastic scattering on specially prepared surfaces and nanoparticles/ nanodroplets levitating above them, might provide a unique method to study surface potentials. The present study had been performed prior to the experiment presented in ref. (1), and strongly motivated this experiment. The new data and their analysis will be published in detail elsewhere.

We consider two parallel corrugated plates and show that a Casimir torque arises when the corrugation directions are not aligned. We follow the scattering approach and calculate the Casimir energy up to second order in the corrugation amplitudes, taking into account nonspecular reflections, polarization mixing and the finite conductivity of the metals. We compare our results with the proximity force approximation, which overestimates the torque by a factor 2 when taking the conditions that optimize the effect. We argue that the Casimir torque could be measured for separation distances as large as 1 µm.

We develop the scattering approach to calculate the exact dispersive Casimir-Polder potential between a ground-state atom and a rectangular grating. Our formalism allows, in principle, for arbitrary values of the grating amplitude and period, and of the atom-grating distance. We compute numerically the potential for a Rb atom on top of a Si grating and compare the results with the potential for a flat surface taken at the local atom-surface distance (proximity force approximation). Except for very short separation distances, the potential is nearly sinusoidal along the direction transverse to the grooves.

PELAKSANAAN PEMERIKSAAN TERHADAP PENYANDANG DISABILITAS MENTAL KORBAN TINDAK PIDANA PERKOSAAN OLEH PENYIDIK KEPOLISIAN NEGARA REPUBLIK INDONESIA (Studi Kasus di Unit PPA POLRESTA Padang) (Novia Ulva, 1310111061, Fakultas Hukum Universitas Andalas, PK V (Sistem Peradilan Pidana), 79 Halaman, 2017) ABSTRAK Kepolisian merupakan suatu sub sistem dalam sistem pearadilan pidana yang memiliki kewenangan untuk melakukan penyidikan, pada tahap penyidikan terdapat proses pemeriksaan terhadap tersangka, korban/saksi korban guna untukmembuat terang suatu tindak pidana. Dalam tindak pidana perkosaan terhadap penyandang disabilitas diperlukan adanya teknik atau cara khusus yang dilakukan oleh penyidik kepolisian, terutama terhadap korban penyandang disabilitas yang mana memiliki banyak keterbatasan dari orang biasa. Menurut Pasal 1 ayat (1) Undang-Undang Nomor 8 Tahun 2016 tentang Penyandang Disabilitas bahwa “Penyandang Disabilitas adalah setiap orang yang mengalami keterbatasan fisik, intelektu...

ABSTRACT
This theoretical work corresponds to the hope of extracting an energy present throughout the universe: that of the quantum vacuum.    With the energy of the quantum vacuum as the only source, this article shows that it is theoretically possible, without contradicting EMMY NOETHER's theorem:                                       1/ to maintain a continuous periodic vibration of a piezoelectric bridge embedded at its two ends,                                                               2/ to extract a usable electrical power from it.                                                                 These vibrations of the sensor part of the proposed MEMS have nothing in common with an impossible macroscopic "perpetual motion" because the energy of the quantum vacuum permanently powers the system.
They are obtained by automatically controlling the deformation of a piezoelectric bridge. This cyclic deformation is created thanks to the Casimir force FCA, omnipresent, permanent and attractive, between two electrodes. This force FCA is controlled by an automatic Coulomb repulsive force FCO which is applied, thanks to the closure of a switch n°1 on a third electrode called Coulomb.                                                                                     The FCO Coulomb’s force derives from the electric charges generated by the deformation of the piezoelectric bridge. The FCO force is in the opposite direction and with a greater intensity than the FCA. The FCO force appears and disappears at predetermined positions z1 and z2, thanks to the very close switching of two switches which automatically switch by the action of the electric charges appearing on the deformed piezoelectric bridge.                                           The resultant of the applied forces, FCO - FCA then straightens the bridge and gives it a kinetic energy, giving it an inertia which will be dissipated by the FCA force.                       The deformation of the piezoelectric bridge being reduced as well as its electric charges, the switch n°1 opens again, immediately after its closure. Very quickly afterwards, the Coulomb electrode is then brought to ground, thanks to the switching - via an R.L.C circuit - of the switch n°2. The Fco force therefore disappears very quickly after its appearance. The kinetic energy acquired by the structure gives it an inertia which allows it to find or slightly exceed the initial position.                             The Casimir force, still present, then deforms the structure again. The system starts to vibrate.                                                                           Each time switch n°2 is closed to ground, a current and voltage peak is generated. These periodic power peaks supply an autonomous electronic circuit (without any power supply) which transforms these signals into a usable DC voltage.                                                                                 In this article we will exclusively present the energy balance of the structure, and we will show that - unless mistaken - this balance is consistent with Miss Emmy Noether's fundamental theorem.                                                                For the parts:                                                 1/ Putting into equations the dynamic behavior of the structure                                                               2/ Creation of autonomous electronics for signal shaping                                                       3/ Manufacturing microtechnology [7] [8] [9]                                               See the articles published on Academia at the addresses:                        https://www.academia.edu/94163820 , https://www.academia.edu /94166557