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Table of contents

Volume 115

Number 2, July 2016

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00 General

20001

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Basing on the analogue Landau levels for a neutral particle possessing an induced electric dipole moment, we show that displaced states can be built in the presence of electric and magnetic fields. Besides, the Berry phase associated with these displaced quantum states is obtained by performing an adiabatic cyclic evolution in series of paths in parameter space.

20002

We introduce the third independent exactly solvable hypergeometric potential, after the Eckart and the Pöschl-Teller potentials, which is proportional to an energy-independent parameter and has a shape that is independent of this parameter. The general solution of the Schrödinger equation for this potential is written through fundamental solutions each of which presents an irreducible combination of two Gauss hypergeometric functions. The potential is an asymmetric step-barrier with variable height and steepness. Discussing the transmission above such a barrier, we derive a compact formula for the reflection coefficient.

20003

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Detailed numerical simulations of intrinsic Josephson junctions of high-temperature superconductors under external electromagnetic radiation are performed taking into account a charge imbalance effect. We demonstrate that the charge imbalance is responsible for a slope in the Shapiro step in the IV-characteristic. The value of slope increases with a nonequilibrium parameter. Coupling between junctions leads to the distribution of the slope's values along the stack. The nonperiodic boundary conditions shift the Shapiro step from the canonical position determined by $V_{ss}=\hbar f /(2e)$ , where f is a frequency of external radiation. This fact makes the interpretation of the experimentally found Shapiro step shift by the charge imbalance effect ambiguous.

20004

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We present a fluctuation-dissipation theorem (FDT) for nonequilibrium quantum systems with detailed-balance breaking, which deviates from the conventional form of the FDT for equilibrium systems preserving detailed balance. Using the phase space formulation of quantum mechanics and the potential-flux landscape framework, we find that the response function of nonequilibrium quantum systems to external perturbations contains a nontrivial contribution from the quantum curl flux quantifying detailed-balance breaking in the steady state, in addition to the correlation function of observables in the steady state representing the contribution of spontaneous fluctuations which is also present in the equilibrium FDT. We illustrate our general formalism with a harmonic oscillator coupled to two heat baths, and show that the nonequilibrium FDT reduces to the conventional expression at the equilibrium condition when the flux contribution vanishes.

20005

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We consider a class of relativistic quantum systems of ring geometry with mass confinement, subject to a magnetic flux. Such a system supports a family of boundary modes with edge-dependent currents and spin polarization as the spinor-wave analog of the whispering-gallery modes. While these states are remarkably robust against random scattering, boundary deformations and/or bulk disorders can couple the two oppositely circulating base states. Superposition of the two states can be realized by sweeping an external magnetic flux. We also address the issue of decoherence and articulate a possible experimental scheme based on 3D topological insulators.

20006

In 2015, Anderson et al. (EPL, 110 (2015) 10002) have claimed to find evidence for periodic sinusoidal variations (period = 5.9 years) in measurements of Newton's gravitational constant. These claims have been disputed by Pitkin (EPL, 111 (2015) 30002). Using the Bayesian model comparison, he argues that a model with an unknown Gaussian noise component is favored over any periodic variations by more than e30. We re-examine the claims of Anderson et al. using frequentist model comparison tests, both with and without errors in the measurement times. Our findings lend support to Pitkin's claim that a constant term along with an unknown systematic offset provides a better fit to the measurements of Newton's constant, compared to any sinusoidal variations.

20007

and

We study the evolution of 3d weakly interacting bosons at finite chemical potential with the stochastic Gross-Pitaevskii equation. We fully characterise the vortex network in an out of equilibrium. At high temperature the filament statistics are the ones of fully-packed loop models. The vortex tangle undergoes a geometric percolation transition within the thermodynamically ordered phase. After infinitely fast quenches across the thermodynamic critical point deep into the ordered phase, we identify a first approach towards a state that is numerically indistinguishable from the one of the critical threshold, a later coarsening process that does not alter the fractal properties of the long vortex loops, and a final approach to equilibrium. Our results are also relevant to the statistics of linear defects in type-II superconductors, magnetic materials and cosmological models.

20008

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We have studied the time evolution of electron wave packets in silicene under perpendicular magnetic and electric fields to characterize topological-band insulator transitions. We have found that at the charge neutrality points, the periodicities exhibited by the wave packet dynamics (classical and revival times) reach maximum values, and that the electron currents reflect the transition from a topological insulator to a band insulator. This provides a signature of topological phase transition in silicene that can be extended to other 2D Dirac materials isostructural to graphene and with a buckled structure and a significant spin-orbit coupling.

20009

We present analytical and numerical results on the joint dynamics of two coupled Duffing oscillators with nonlinearity of opposite signs (hardening and softening). In particular, we focus on the existence and stability of synchronized oscillations where the frequency is independent of the amplitude. In this regime, the amplitude-frequency interdependence (a-f effect) —a noxious consequence of nonlinearity, which jeopardizes the use of micromechanical oscillators in the design of time-keeping devices— is suppressed. By means of a multiple time scale formulation, we find approximate conditions under which frequency stabilization is achieved, characterize the stability of the resulting oscillations, and compare with numerical solutions to the equations of motion.

20010

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The scattering of 1D matter wave bright solitons on attractive potentials enables one to populate bound states, a feature impossible with noninteracting wave packets. Compared to noninteracting states, the populated states are renormalized by the attractive interactions between atoms and keep the same topology. This renormalization can even transform a virtual state into a bound state. By switching off adiabatically the interactions, the trapped wave packets converge towards the true noninteracting bound states. Our numerical studies show how such scattering experiments can reveal and characterize the surface states of a periodic structure whose translational invariance has been broken. We provide evidence that the corresponding 3D regime should be accessible with current techniques.

20011

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Oscillation quenching including amplitude death (AD) and oscillation death (OD) in addition to the transition processes between them have been hot topics in aspect of chaos control, physical and biological applications. The effects of dual-channel coupling on the AD and OD dynamics regimes, and their transition processes in coupled nonidentical oscillators are explored numerically and theoretically. Our results indicate that an additional repulsive coupling tends to shrink the AD domain while it enlarges the OD domain, however, an additional attractive coupling acts inversely. As a result, the transitions from AD to OD are replaced by transitions from oscillation state (OS) to AD or from OS to OD in the dual-channel coupled oscillators with different frequency mismatches. Our results are helpful to better understand the control of AD and OD and their transition processes.

20012

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Recently developed techniques allow for simultaneous measurements of the positions of all ultra-cold atoms in a trap with high resolution. Each such single-shot experiment detects one element of the quantum ensemble formed by the cloud of atoms. Repeated single-shot measurements can be used to determine all correlations between particle positions as opposed to standard measurements that determine particle density or two-particle correlations only. In this paper we discuss the possible outcomes of such single-shot measurements in the case of cloud of ultra-cold noninteracting Fermi atoms. We show that the Pauli exclusion principle alone leads to correlations between particle positions that originate from unexpected spatial structures formed by the atoms.

10 The physics of elementary particles and fields

21001

The aim of this letter is to discuss the recently observed excess at 750 GeV by both CMS and ATLAS in the light of the dual standard model. Within this framework it is natural to introduce neutral spin-0 and/or spin-2 SU(2) glue mesons which could easily account for this observation if it is confirmed. The model predicts that these glue mesons would be part of SU(2) triplets and that there must thus be charged counterparts of these glue mesons carrying a QED charge of ±1 with a spin 0 and/or 2 as well.

21002

and

We present a theoretical approach to obtain the decay properties of D and Ds mesons. As the Cornell potential includes confinement because of the linear potential, and it also includes the single-gluon exchange potential, which is the Coulomb potential, we have considered this potential for the study of mesonic systems. The two-parameter variational method has been applied to investigate the masses and the decay properties of mesons. It has been observed that the predictions of the masses and decay widths are consistent with other model predictions as well as with the known experimental values.

21003

and

We demonstrate that the gauge-fixed Lagrangian of the Christ-Lee model respects four fermionic symmetries, namely; (anti-)BRST symmetries, (anti-)co-BRST symmetries within the framework of BRST formalism. The appropriate anticommutators amongst the fermionic symmetries lead to a unique bosonic symmetry. It turns out that the algebra obeyed by the symmetry transformations (and their corresponding conserved charges) is reminiscent of the algebra satisfied by the de Rham cohomological operators of differential geometry. We also provide the physical realizations of the cohomological operators in terms of the symmetry properties. Thus, the present model provides a simple model for the Hodge theory.

40 Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics

24001

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We propose and theoretically investigate a novel one-dimensional photonic crystal nanocylinder cavity (PCNC) that can support the second-order transverse-electric-like (TE2) mode. Three-dimensional finite-difference time-domain simulations show that the TE2 mode of the PCNC possesses an ultrahigh quality factor of 1.22 × 108 and a small mode volume of $0.98(\lambda /n)^3$ when the PCNC is made of high-index material of silicon. For the PCNCs which are made of low-index materials, the corresponding quality factors of TE2 modes reach the highest values relative to previously demonstrated PhC nanobeam cavities with the same low-index materials to the best of our knowledge. We believe the PCNC will be a highly promising candidate for low-threshold high-speed nanoscale lasers and cavity optomechanics.

24002

, and

We study the thermalization and the Bose-Einstein condensation of a paraxial, spectrally narrow beam of quantum light propagating in a lossless bulk Kerr medium. The spatiotemporal evolution of the quantum optical field is ruled by a Heisenberg equation analogous to the quantum nonlinear Schrödinger equation of dilute atomic Bose gases. Correspondingly, in the weak-nonlinearity regime, the phase-space density evolves according to the Boltzmann equation. Expressions for the thermalization time and for the temperature and the chemical potential of the eventual Bose-Einstein distribution are found. After discussing experimental issues, we introduce an optical setup allowing the evaporative cooling of a guided beam of light towards Bose-Einstein condensation. This might serve as a novel source of coherent light.

60 Condensed matter: structural, mechanical and thermal properties

26001

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It has been recently established that the size of the defects created under ion irradiation follows a scaling law (Sand A. E. et al., EPL, 103 (2013) 46003; Yi X. et al., EPL, 110 (2015) 36001). A critical constraint associated with its application to phenomena occurring over a broad range of irradiation conditions is the limitation on the energy of incident particles. Incident neutrons or ions, with energies exceeding a certain energy threshold, produce a complex hierarchy of collision subcascade events, which impedes the use of the defect cluster size scaling law derived for an individual low-energy cascade. By analyzing the statistics of subcascade sizes and energies, we show that defect clustering above threshold energies can be described by a product of two scaling laws, one for the sizes of subcascades and the other for the sizes of defect clusters formed in subcascades. The statistics of subcascade sizes exhibits a transition at a threshold energy, where the subcascade morphology changes from a single domain below the energy threshold, to several or many sub-domains above the threshold. The number of sub-domains then increases in proportion to the primary knock-on atom energy. The model has been validated against direct molecular-dynamics simulations and applied to W, Fe, Be, Zr and sixteen other metals, enabling the prediction of full statistics of defect cluster sizes with no limitation on the energy of cascade events. We find that populations of defect clusters produced by the fragmented high-energy cascades are dominated by individual Frenkel pairs and relatively small defect clusters, whereas the lower-energy non-fragmented cascades produce a greater proportion of large defect clusters.

26002

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First-principles calculations are employed to investigate the phonon transport of Cu2GeSe3. The lattice thermal conductivities of Cu2GeSe3 are reproduced. In Cu2GeSe3, the low-frequency phonons lower than 88 cm−1, which comprise of most acoustic modes and a few optical modes, contribute more than 90% to the overall lattice thermal conductivity in Cu2GeSe3. According to the calculations of phonon transport, nanostructuring may be an effective way to reduce the lattice thermal conductivity of Cu2GeSe3. Particularly, at 300 K, the nanostructuring with length scale 100 nm (10 nm) would possibly reduce the thermal conductivity by more than 40% (80%) for Cu2GeSe3. With increase of temperature, the effect of nanostructuring on reducing the lattice thermal conductivity will diminish, due to the decrease in the phonon mean-free path. We further speculate that phonon-band engineering by doping with heavy elements such as Pb may further reduce the lattice thermal conductivity. Our work facilitates deep understanding of the mechanisms of effective reduction of the thermal conductivity by nanostructuring or doping, and helps design better thermoelectric materials.

26003

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Ferroelectric tunnel junction (FTJ) is a breakthrough for addressing the nondestructive read in the ferroelectric random access memories. However, FTJs with nearly ideal characteristics have only been demonstrated on perovskite heterostructures that are deposited on closely lattice-matched and non-silicon substrates, or silicon substrates with epitaxial multilayer. In order to promote the application of FTJs, we develop a polycrystalline FTJ with ultrathin bottom electrode, in which the resistance variations exceed two orders of magnitude. And we achieve two stable logic states written and read easily using voltage pulses. Especially the device integrates with the silicon technology in modern microelectronics. Our results suggest new opportunities for ferroelectrics as nonvolatile resistive switching memory.

70 Condensed matter: electronic structure, electrical, magnetic, and optical properties

27001

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Perspective

Techniques in time- and angle-resolved photoemission spectroscopy have facilitated a number of recent advances in the study of quantum materials. We review developments in this field related to the study of incoherent nonequilibrium electron dynamics, the analysis of interactions between electrons and collective excitations, the exploration of dressed-state physics, and the illumination of unoccupied band structure. Future prospects are also discussed.

27002

The relation between the condensation energy (CE) and Tc of a phase transition reveals a fundamental nature of the transition. In view of this, the recent experimental observation of the non-BCS scaling relation of the CE vs. $T_c~(\Delta E \sim T_c^{3.5})$ with about forty different samples of the Fe-based superconductors (Xing J. et al., Phys. Rev. B, 89 (2014) 140503) was intriguing and strongly hinted at a non-BCS pairing mechanism. In this paper, we have studied the CE and Tc of the multiband BCS model and found that the observed anomalous scaling relation $\Delta E \sim T_c^{3.5}$ is well reproduced by the two-band BCS model paired by a dominant repulsive interband interaction $(V_{inter} > V_{intra}>0)$ . Our result implies that this seemingly non-BCS–like scaling behavior of $\Delta E \sim T_c^{3.5}$ , on the contrary to the common expectations, is in fact a strong experimental evidence that the pairing mechanism of the Fe-based superconductors is genuinely a BCS mechanism, meaning that the Cooper pairs are formed by the itinerant carriers glued by a pairing interaction.

27003

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With attractive features like high energy density and flexibility, dielectric elastomer generators (DEGs) have been designed to harvest mechanical energy from diverse sources. However, their energy harvesting performance could be limited by the material viscoelasticity and various failure modes. Adopting the finite-deformation viscoelasticity model, this work presents a theoretical framework for analyzing the performance of a DEG with a "triangular" harvesting scheme. Simulation results reveal that choosing an appropriate in-plane stretch ratio for the onset of the discharging process can raise the harvested energy of DEGs. It is also found that the energy conversion efficiency of a DEG can be markedly improved by avoiding loss-of-tension of elastomer during the operation of energy harvesting.

27004

and

We study persistent currents in a Josephson junction array wrapped around a cylinder. The T = 0 quantum statistical mechanics of the array is equivalent to the statistical mechanics of a classical xy spin system in 2+1 dimensions at the effective temperature $T^{*}=\sqrt{2JU}$ , with J being the Josephson energy of the junction and U being the charging energy of the superconducting island. It is investigated analytically and numerically on lattices containing over one million sites. For weak disorder and $T^{*}\ll J$ the dependence of the persistent current on disorder and $T^{*}$ computed numerically agrees quantitatively with the analytical result derived within the spin-wave approximation. The high-$T^{*}$ and/or strong-disorder behavior is dominated by instantons corresponding to the vortex loops in 2 + 1 dimensions. The current becomes destroyed completely at the quantum phase transition into the Cooper-pair insulating phase.

27005

and

We show explicitly how a fixed point can be constructed in scalar $g\varphi^4$ theory from the solutions to a nonlinear eigenvalue problem. The fixed point is unstable and characterized by $\nu=2/d$ (correlation length exponent), $\eta=1/2-d/8$ (anomalous dimension). For d = 2, these exponents reproduce to those of the Ising model which can be understood from the codimension of the critical point. The testable prediction of this fixed point is that the specific heat exponent vanishes. 2d critical Mott systems are well described by this new fixed point.

27006
The following article is Open access

, , , , , , , , , et al

We report the structural, electronic, and magnetic study of Cr-doped Sb2Te3 thin films grown by a two-step deposition process using molecular-beam epitaxy (MBE). The samples were investigated using a variety of complementary techniques, namely, x-ray diffraction (XRD), atomic force microscopy, SQUID magnetometry, magneto-transport, and polarized neutron reflectometry (PNR). It is found that the samples retain good crystalline order up to a doping level of $x=0.42$ (in CrxSb2−xTe3), above which degradation of the crystal structure is observed by XRD. Fits to the recorded XRD spectra indicate a general reduction in the c-axis lattice parameter as a function of doping, consistent with substitutional doping with an ion of smaller ionic radius. The samples show soft ferromagnetic behavior with the easy axis of magnetization being out-of-plane. The saturation magnetization is dependent on the doping level, and reaches from ${\sim}2\ \mu_\text{B}$ to almost $3\ \mu_\text{B}$ per Cr ion. The transition temperature $(T_{\mathrm{c}})$ depends strongly on the Cr concentration and is found to increase with doping concentration. For the highest achievable doping level for phase-pure films of $x=0.42$ , a $T_{\mathrm{c}}$ of 125 K was determined. Electric transport measurements find surface-dominated transport below ∼10 K. The magnetic properties extracted from anomalous Hall effect data are in excellent agreement with the magnetometry data. PNR studies indicate a uniform magnetization profile throughout the film, with no indication of enhanced magnetic order towards the sample surface.

27007

, and

We have successfully synthesized the quasi-1D cobalt carbide Sc3CoC4 by using the arc-melting technique which is similar to that of the previous reports. An incomplete superconducting transition is detected at ambient pressure. In addition, two anomalies have been observed at 72 K and 143 K both from resistivity and magnetic susceptibility measurements. According to previous studies, it was argued that they correspond to the 1D Peierls-type distortion and charge-density-wave transitions, respectively. By applying a pressure, the transition at about 72 K is quickly suppressed, which is accompanied by the occurrence of a complete superconducting transition at about 4.5 K. Moreover, the DC magnetic susceptibility under high pressures also reveals the enhancement of superconductivity. We attribute this enhancement of superconductivity to the suppression of the Peierls-type distortion at about 72 K and probably together with the promoted Josephson coupling between the [CoC4] one-dimensional ribbons.

27008

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We study the possible superconducting pairing symmetry mediated by spin and charge fluctuations on the honeycomb lattice using the extended Hubbard model and the random-phase-approximation method. From 2% to 20% doping levels, a spin-singlet $d_{x^{2}-y^{2}}+id_{xy}$ -wave is shown to be the leading superconducting pairing symmetry when only the on-site Coulomb interaction U is considered, with the gap function being a mixture of the nearest-neighbor and next-nearest-neighbor pairings. When the offset of the energy level between the two sublattices exceeds a critical value, the most favorable pairing is a spin-triplet f-wave which is mainly composed of the next-nearest-neighbor pairing. We show that the next-nearest-neighbor Coulomb interaction V is also in favor of the spin-triplet f-wave pairing.

27009

, , and

The modulation of the band gap in the two-dimensional carbon materials is of importance for their applications as electronic devices. By first-principles calculations, we propose a model to control the band gap size of γ-graphyne. The model is named as p-n codoping, i.e., using B and N atoms to codope into γ-graphyne. After codoping, the B atom plays the role of p dopant and the N atom acts as n dopant. The Fermi energy level returns around the forbidden zone and the band gap of γ-graphyne becomes bigger or smaller. Moreover, the gaps exhibit an oscillating behaviour in the different codoping configurations. The proposed model serves as new insights for a better modulation of the electronic properties of 2D carbon materials.

27010

, and

It has been found experimentally that in intense femtosecond laser fields the surface plasmon dispersion has an oscillatory character as a function of the exciting laser intensity. It has been interpreted as the result of the dynamic screening of electrons by the strong laser field. A simple model is described in addition to the experimental results, being in good agreement with these findings. The results imply an electron effective mass of around 10 percent lighter than the free electron mass. The effective mass decreases with increasing laser intensity.

80 Interdisciplinary physics and related areas of science and technology

28001

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Assembly and stability of mitotic spindle are governed by the interplay of various intra-cellular forces, e.g. the forces generated by motor proteins by sliding overlapping anti-parallel microtubules (MTs) polymerized from the opposite centrosomes, the interaction of kinetochores with MTs, and the interaction of MTs with the chromosome arms. We study the mechanical behavior and stability of spindle assembly within the framework of a minimal model which includes all these effects. For this model, we derive a closed-form analytical expression for the force acting between the centrosomes as a function of their separation distance and we show that an effective potential can be associated with the interactions at play. We obtain the stability diagram of spindle formation in terms of parameters characterizing the strength of motor sliding, repulsive forces generated by polymerizing MTs, and the forces arising out of the interaction of MTs with kinetochores. The stability diagram helps in quantifying the relative effects of the different interactions and elucidates the role of motor proteins in formation and inhibition of spindle structures during mitotic cell division. We also predict a regime of bistability for a certain parameter range, wherein the spindle structure can be stable for two different finite separation distances between centrosomes. This occurrence of bistability also suggests the mechanical versatility of such self-assembled spindle structures.

28002

, and

The behaviour of an active polar suspension in a fluid film is analysed in the vanishing Reynolds number limit. We perform a detailed study of the transitions to spontaneously flowing steady states and their associated density variations. Beyond the onset of instability, we find a new transverse symmetry breaking of the flow generated in the film. This spontaneous symmetry breaking is observed despite symmetric boundary conditions (with respect to orientation) on either side of the film. We study this new phenomenon by means of numerical simulations and nonlinear theory, showing that it can be ascribed to the nonlinear coupling, characteristic of polar active systems, of the density gradients with the flow velocity and the orientation field. As such a theoretical analysis based on linear stability arguments typically used to identify phase boundaries is unable to describe it. An extension of the theory to allow for higher-density regimes is also proposed.

28003

Diamond defect spins have emerged as potential qudits (d-dimensional quantum bit) in quantum information and quantum computing. A new scheme is proposed for realizing entangled states of GHZ (Greenberger-Horne-Zeilinger) class in a 3-qudit solid-state register. The qudits are the electron spin-1 carried by the negatively charged nitrogen-vacancy color center (NV−1) in diamond and the nuclear spin-$\frac{1}{2}$ of two carbon-13 impurities in the first neighbour shell. Multipartite entanglements between qudits are obtained by bringing the spin system in the vicinity of a level anticrossing. The degree of entanglement between all three qudits is quantified rigorously. GHZ and GHZ-like entangled states have applications in quantum communication and computation protocols.

28004

and

The Braess Paradox is the counterintuitive phenomenon that can occur in a user-optimized network system, such as a transportation network, where adding an additional link to the network increases the cost (travel time) for every user. In electrical circuits, electrons, analogous to drivers in a transportation network, traverse the network so that no electron can unilaterally change its cost (voltage drop) from an origin to a destination. In this paper, we show that the Braess Paradox can occur in electrical circuits consisting of diodes and resistors. We report measurements confirming the occurrence of the Braess Paradox in two different circuits, one with highly nonlinear link cost functions ($I\text{-}V$ characteristics). These measurements show that the voltage increases, rather than decreases, when a link is added to the circuit under constant demand (current). This discovery identifies novel circuits in which the voltage and current can be independently adjusted. It also yields insights into the Braess Paradox and transportation networks through a new computational mechanism.

28005

and

Two-dimensional binary mixtures made up of particles carrying similar parallel dipole moments are investigated. Using Monte Carlo simulations a detailed structural analysis based on partial pair distribution functions and microstructure snapshots is presented for high dipolar coupling. At equimolar composition, the relevance of the coexistence of triangular superlattices with stoichiometry AB2 and A2B is revealed, with A(B) standing for the large(small) dipole moments. This key finding is in excellent qualitative agreement with the zero-temperature theoretical prediction of Assoud L. et al., EPL, 80 (2007) 48001. These structures are detectable in experiments on colloidal and granular matter.

28006

, , , and

The influence of annealing temperature on the electrical properties of tin silicon oxide (TSO) thin-film transistors (TFTs) and the corresponding bias stress stability have been investigated. With increasing annealing temperature, the TSO films present a structure which is closer to crystallization, and it is conducive to the improvement of the mobility of TSO TFTs. Meanwhile, the positive bias stress (PBS) stability of TSO TFTs is ameliorated due to the decreasing traps at the interface of dielectric layer and channel layer. The threshold voltage shifts in opposite direction after being stressed under negative bias stress (NBS), which is due to the competition between electrons captured by defects related to oxygen vacancies in the channel layer and water molecule adsorption on the back channel.

90 Geophysics, astronomy, and astrophysics

29001

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The gravito-electrostatic sheath (GES) model, previously formulated to investigate the equilibrium properties of the Sun and its unbounded atmosphere coupled via the interfacial solar surface boundary (SSB) under the gravito-electrostatic interplay, is re-examined. It is modified, for the first time, with the self-consistent inclusion of turbu-magnetic pressure effects originating from intrinsic continuous instability processes. The role of the new effects is interestingly realized through considerable changes in the dynamic properties of the solar plasma system on both the bounded and unbounded scales. The SSB, as a result of the outward turbu-magnetic action relative to the inward self-gravitating one, is found to shift radially outwards by 5.71% relative to the sheer GES model, and by 7.50% inwards relative to the pure uniformly magnetized counterpart. The sonic point moves inwards by 30% in the former, and by 24% in the latter; respectively. It is further found that the floating surface and floating potential increase by 47% each relative to the GES; and by 27% and 160% relative to the pure magnetic case; respectively. The implications and applications are discussed in the panoptical light of real astronomical observations alongside the facts, faults and future refinements.