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In this work, a Lattice-Boltzmann-Method (LBM) model for simulating hysteresis in a proton exchange membrane fuel cell (PEMFC) electrode is presented. One of the main challenges hindering study of the cathode catalyst layer (CCL) in PEMFCs is the lack of understanding of two-phase transport and how it affects electrochemical performance. Previously, the microstructure details needed to build an accurate mesoscale model to examine such phenomena have eluded researchers; however, with advances in tomography and focused-ion-beam scanning-electron-microscopy (FIB-SEM), reconstruction of the complex porous media has become possible. Using LBM with these representations, the difficult problem of catalyst layer capillary hysteresis can be examined. In two-phase capillary hysteresis, both the equilibrium saturation position as well as its absolute value depends on the wetting history. Based on the models, it is ascertained that at lower capillary numbers, the liquid begins to undergo capillary fingering--only above a capillary pressure of 5 MPa, a regime change into stable displacement is observed. As capillary fingering does not lead to uniform removal of liquid, the prediction is that because high capillary pressures are needed to change to the regime of stable displacement, wicking is not as effective as the primary means of water removal. [ABSTRACT FROM AUTHOR]

Batch production of continuous and uniform graphene films is critical for the application of graphene. Chemical vapor deposition (CVD) has shown great promise for mass producing high-quality graphene films. However, the critical factors affected the uniformity of graphene films during the batch production need to be further studied. Herein, we propose a method for batch production of uniform graphene films by controlling the gaseous carbon source to be uniformly distributed near the substrate surface. By designing the growth space of graphene into a rectangular channel structure, we adjusted the velocity of feedstock gas flow to be uniformly distributed in the channel, which is critical for uniform graphene growth. The monolayer graphene film grown inside the rectangular channel structure shows high uniformity with average sheet resistance of 345 Ω sq−1 without doping. The experimental and simulation results show that the placement of the substrates during batch growth of graphene films will greatly affect the distribution of gas-phase dynamics near the substrate surface and the growth process of graphene. Uniform graphene films with large-scale can be prepared in batches by adjusting the distribution of gas-phase dynamics. [ABSTRACT FROM AUTHOR]

Reynolds stress is a key facet of turbulence self-organization. In the magnetized plasmas of controlled fusion devices, the zonal flows that are driven by the averaged Reynolds stress modify the confinement performance. We address this problem with full-f gyrokinetic simulations of ion temperature gradient-driven turbulence. From the detailed analysis of the three-dimensional electric potential and transverse pressure fields, we show that the diamagnetic contribution to the Reynolds stress—stemming from finite Larmor radius effects—exceeds the electrostatic contribution by a factor of about two. Both contributions are in phase, indicating that pressure does not behave as a passive scalar. In addition, the Reynolds stress induced by the electric drift velocity is found to be mainly governed by the gradient of the phase of the electric potential modes rather than by their magnitude. By decoupling Reynolds stress drive and turbulence intensity, this property indicates that a careful analysis of phase dynamics is crucial in the interpretation of experiments and simulations. [ABSTRACT FROM AUTHOR]

The study of hyperbolic waves involves various notions which help characterise how these structures evolve. One important facet is the notion of genuine nonlinearity, namely the ability for shocks and rarefactions to form instead of contact discontinuities. In the context of the Whitham modulation equations, this paper demonstrate that a loss of genuine nonlinearity leads to the appearance of a dispersive set of dynamics in the form of the modified Korteweg de-Vries equation governing the evolution of the waves instead. Its form is universal in the sense that its coefficients can be written entirely using linear properties of the underlying waves such as the conservation laws and linear dispersion relation. This insight is applied to two systems of physical interest, one an optical model and the other a stratified hydrodynamics experiment, to demonstrate how it can be used to provide insight into how waves in these systems evolve when genuine nonlinearity is lost. [ABSTRACT FROM AUTHOR]

Although much empirical evidence has demonstrated that p53 plays a key role in tumor suppression, the dynamics and function of the regulatory network centered on p53 have not yet been fully understood. Here, we develop a Boolean network model to reproduce the two-phase dynamics of the p53 network in response to DNA damage. In particular, we map the fates of cells into two types of Boolean attractors, and we find that the apoptosis attractor does not exist for minor DNA damage, reflecting that the cell is reparable. As the amount of DNA damage increases, the basin of the repair attractor shrinks, accompanied by the rising of the apoptosis attractor and the expansion of its basin, indicating that the cell becomes more irreparable with more DNA damage. For severe DNA damage, the repair attractor vanishes, and the apoptosis attractor dominates the state space, accounting for the exclusive fate of death. Based on the Boolean network model, we explore the significance of links, in terms of the sensitivity of the two-phase dynamics, to perturbing the weights of links and removing them. We find that the links are either critical or ordinary, rather than redundant. This implies that the p53 network is irreducible, but tolerant of small mutations at some ordinary links, and this can be interpreted with evolutionary theory. We further devised practical control schemes for steering the system into the apoptosis attractor in the presence of DNA damage by pinning the state of a single node or perturbing the weight of a single link. Our approach offers insights into understanding and controlling the p53 network, which is of paramount importance for medical treatment and genetic engineering.

We study a reduced electrostatic fluid model for the tokamak scrape-off layer, which incorporates temperature gradient and vorticity gradient as two free energy fields. Two scenarios of field coupling are addressed: (1) sheath condition; (2) vortex wave coupling. For the sheath condition induced field coupling, the poloidal $\mathbf{E} \times \mathbf{B}$ flow shear is coupled with the temperature gradient. Combining an eigenmode analysis and the nonlinear phase dynamics approach, our findings indicate that in the absence of a vorticity gradient, the overall effect of the sheath condition induced flow shear can either stabilize or destabilize the interchange mode, depending on the competition between the flow shear suppression and the temperature gradient driving. This is different from the case where the gradient drive and shear damping are decoupled. When the field coupling is mediated by wave interactions, by setting an idealized step-like temperature and vorticity profiles, a joint mode forms through resonant interaction between the interfacial waves driven by the temperature and vorticity gradients, respectively. Near the phase locking condition, the joint mode can be more unstable than pure temperature gradient driven mode.

Edge transport bifurcation induced by external biasing is explored with self-consistent turbulence simulations in a flux-driven system with both closed and open magnetic field lines. Without bias, the nonlinear evolution of interchange turbulence produces large-scale turbulent eddies, leading to the high levels of radial transport in the edge region. With sufficiently strong biasing, a strong suppression of turbulence is found. The plasma potential structures are strongly modified with the generation of sheared mean flows at the plasma edge. Consequently, the turbulence-driven flux is decreased to a much lower level, indicating a transition to a state of reduced transport. The simulations show that the dynamics of the phase and amplitude of fluctuations play a crucial role in the mechanism of transport suppression driven by biasing. [ABSTRACT FROM AUTHOR]

Two parallel stacks of coupled Josephson junctions (JJs) are investigated to clarify the physics of transitions between the rotating and oscillating states and their effect on the IV-characteristics of the system. The detailed study of phase dynamics and bias dependence of the superconducting and diffusion currents allows one to explain all features of simulated IV-characteristics and demonstrate the correspondence in their behavior. The coupling between JJ in the stacks leads to the branching of IV-characteristics and a decrease in the hysteretic region. The crucial role of the diffusion current in the formation of the IV-characteristic of the parallel stacks of coupled JJs is demonstrated. We discuss the effect of symmetry in a number of junctions in the stacks and show a decrease of the branching in the symmetrical stacks. The observed effects might be useful for development of superconducting electronic devices based on intrinsic JJs. [ABSTRACT FROM AUTHOR]

Swarmalators are entities with the simultaneous presence of swarming and synchronization that reveal emergent collective behavior due to the fascinating bidirectional interplay between phase and spatial dynamics. Although different coupling topologies have already been considered, here we introduce time-varying competitive phase interaction among swarmalators where the underlying connectivity for attractive and repulsive coupling varies depending on the vision (sensing) radius. Apart from investigating some fundamental properties like conservation of center of position and collision avoidance, we also scrutinize the cases of extreme limits of vision radius. The concurrence of attractiveâ€"repulsive competitive phase coupling allows the exploration of diverse asymptotic states, like static Ď€, and mixed phase wave states, and we explore the feasible routes of those states through a detailed numerical analysis. In sole presence of attractive local coupling, we reveal the occurrence of static cluster synchronization where the number of clusters depends crucially on the initial distribution of positions and phases of each swarmalator. In addition, we analytically calculate the sufficient condition for the emergence of the static synchronization state. We further report the appearance of the static ring phase wave state and evaluate its radius theoretically. Finally, we validate our findings using Stuartâ€"Landau oscillators to describe the phase dynamics of swarmalators subject to attractive local coupling. [ABSTRACT FROM AUTHOR]

The high-velocity oxygen fuel (HVOF) thermal spray is used for a particulate deposition process in which micro-sized particles are propelled and heated in a supersonic combusting gas stream. It is characterized by high gas velocity and high density and is being used in an increasing variety of coating applications, such as ceramic and composite coatings, to improve wear and abrasion resistance. The particle temperature and velocity are two of the most important parameters in HVOF thermal spraying, which affect the quality of the coatings. To understand the particle dynamics, it is necessary to study, first, the thermal flow characteristics in the HVOF system. In this study, a numerical analysis is performed to predict the gas dynamic behaviors, and the effect of the geometrical parameter is studied to optimize the nozzle design. [ABSTRACT FROM AUTHOR]

A forward modeling technique is developed for determining the characteristic features of observed MHD modes from the line-of-sight data of the soft x-ray (SXR) tomography diagnostics in the Wendelstein 7-X (W7-X) stellarator. In particular, forward modeling is used to evaluate the poloidal mode numbers m, radial location, poloidal rotation direction and ballooning character of the MHD modes. The poloidal mode structures have been modeled by the radially localized Gaussian-shaped emission regions rotating along the magnetic surfaces. In the present study the cases of rigid-shape emission regions and flexible emission regions are modeled. Various mode phase velocity dependences on the magnetic surface position are simulated. The modeled phase dynamics of line-integrated oscillations and the distribution of oscillation amplitudes are compared with the experimental signals of the SXR cameras which observe the plasma at various viewing angles in the poloidal cross-section. Application of this technique enables describing of the 1–50 kHz modes. In particular, in the discharge W7X-PID 20180918.045 three identified branches with the poloidal mode numbers m= 8, m= 10 and m= 11 localized at ρ ≈ 0.3 are rotating in the clockwise poloidal direction. The present paper reports the first application of the forward modeling technique to the data from the SXR diagnostics in W7-X. The high m-modes are identified by forward modeling in W7-X. [ABSTRACT FROM AUTHOR]

We present an analytical electric field expression to simultaneously control the population and phase dynamics of two-level quantum systems. The presented electric field is obtained by a reverse engineering technique after the desired population and phase evolution pathways of the system have been specified. Upon application of this laser field, the system is driven from an arbitrary quantum state superposition to the desired population distribution; meanwhile the phase of one of the states proceeds according to a predefined path. The robustness of the engineered electric field is demonstrated by numerical simulations on the example of the 3s 3p transition of atomic sodium. Furthermore, the limitations of the presented technique, which arise due to the application of the rotating wave approximation, are thoroughly analyzed and discussed. [ABSTRACT FROM AUTHOR]

We model an overdamped Brownian particle that is subject to resetting facilitated by a ratchet potential on a spatially periodic domain. This asymmetric potential switches on with a constant rate, but switches off again only upon the particle's first passage to a resetting point at the minimum of the potential. Repeating this cycle sustains a non-equilibrium steady-state, as well as a directed steady-state current which can be harnessed to perform useful work. We derive exact analytic expressions for the probability densities of the free-diffusion and resetting phases, the associated currents for each phase, and an efficiency parameter that quantifies the return in current for given power input. These expressions allow us to fully characterise the system and obtain experimentally relevant results such as the optimal current and efficiency. Our results are corroborated by simulations, and have implications for experimentally viable finite-time resetting protocols. [ABSTRACT FROM AUTHOR]

Partial resetting, whereby a state variable x (t) is reset at random times to a value a x (t) , 0 ⩽ a ⩽ 1 , generalizes conventional resetting by introducing the resetting strength a as a parameter. Partial resetting generates a broad family of non-equilibrium steady states (NESS) that interpolates between the conventional NESS at strong resetting (a = 0) and a Gaussian distribution at weak resetting (a → 1). Here such resetting processes are studied from a thermodynamic perspective, and the mean cost associated with maintaining such NESS are derived. The resetting phase of the dynamics is implemented by a resetting potential Φ (x) that mediates the resets in finite time. By working in an ensemble of trajectories with a fixed number of resets, we study both the steady-state properties of the propagator and its moments. The thermodynamic work needed to sustain the resulting NESS is then investigated. We find that different resetting traps can give rise to rates of work with widely different dependencies on the resetting strength a. Surprisingly, in the case of resets mediated by a harmonic trap with otherwise free diffusive motion, the asymptotic rate of work is insensitive to the value of a. For general anharmonic traps, the asymptotic rate of work can be either increasing or decreasing as a function of the strength a, depending on the degree of anharmonicity. Counter to intuition, the rate of work can therefore in some cases increase as the resetting becomes weaker (a → 1) although the work vanishes at a = 1. Work in the presence of a background potential is also considered. Numerical simulations confirm our findings. [ABSTRACT FROM AUTHOR]

In a recent letter (Friedrich et al 2012 Phys. Rev. Lett. 109 138102), a minimal model swimmer has been proposed that propels itself at low Reynolds numbers by the revolving motion of a pair of spheres. The motion of the two spheres can synchronize by virtue of a hydrodynamic coupling that depends on the motion of the swimmer, but is rather independent of direct hydrodynamic interactions. This novel synchronization mechanism could account for the synchronization of a pair of flagella, e.g. in the green algae Chlamydomonas. In this paper, we discuss in detail how swimming and synchronization depend on the geometry of the model swimmer and compute the swimmer design for optimal synchronization. Our analysis highlights the role of broken symmetries in swimming and synchronization. [ABSTRACT FROM AUTHOR]

We study the mean-field dynamics and the reduced-dimension character of two-mode Bose-Einstein condensates (BECs) in highly anisotropic traps. By means of perturbative techniques, we show that the tightly confined (transverse) degrees of freedom can be decoupled from the dynamical equations at the expense of introducing additional effective three-body, attractive, intra- and inter-mode interactions into the dynamics of the loosely confined (longitudinal) degrees of freedom. These effective interactions are mediated by changes in the transverse wave function. The perturbation theory is valid as long as the nonlinear scattering energy is small compared to the transverse energy scales. This approach leads to reduced-dimension mean-field equations that optimally describe the evolution of a two-mode condensate in general quasi-one-dimensional (1D) and quasi-two-dimensional geometries.We use this model to investigate the relative phase and density dynamics of a two-mode, cigar- shaped 87Rb BEC. We study the relative-phase dynamics in the context of a nonlinear Ramsey interferometry scheme, which has recently been proposed as a novel platform for high-precision interferometry. Numerical integration of the coupled, time-dependent, three-dimensional, two-mode Gross-Pitaevskii equations for various atom numbers shows that this model gives a considerably more refined analytical account of the mean-field evolution than an idealized quasi-1D description. [ABSTRACT FROM AUTHOR]

We construct exact ring soliton-like solutions of the cylindrically symmetric (i.e. radial) Gross-Pitaevskii equation with a potential, using the similarity transformation method. Depending on the choice of the allowed free functions, the solutions can take the form of stationary dark or bright rings whose time dependence is in the phase dynamics only, or oscillating and bouncing solutions, related to the second Painlevé transcendent. In each case the potential can be chosen to be time independent. [ABSTRACT FROM AUTHOR]

In this series, Li/Cu microprobes are used to monitor potentials of individual electrodes in situ during high-rate charging of Li-ion cells. Here we focus on capacity-limited charging of these cells to 6C, and present a general treatment of polarization that allows for data reduction and accurate interpolation/extrapolation over a wide range of charge rates. We show that the anode impedance as measured both using this newtreatment and themore established pulsed-current techniques is not significantly changed after high-rate aging of the cell, including the conditions under which Li plating has occurred. Our measurements suggest that the changes in cell and electrode polarization to a large extent occur through nonlinear effects that involve time-delayed processes. An electrochemical model that includes phase dynamics in lithiated graphite is shown to capture some but not all of the observed trends suggesting that important facets of the high-rate behavior need to be included in such models. [ABSTRACT FROM AUTHOR]

The evaporation mechanism at high temperatures is one of the disputable points of the conventional thermal model of laser ablation connecting heat transfer in the target with gas-phase dynamics. A model of supercritical ablation is proposed where the vapour density is limited by a transparency condition. The model is basically laser–vapour coupling in a thin near-surface layer. The experiments on ablation of Au at 193 and 266 nm, Al at 266 nm, and graphite at 1.06 µm can be described by the proposed model. However, optical breakdown is important in graphite ablation at 193 and 248 nm. When the target surface temperature is less than the critical one (typically at fluences less than or about several J cm-2) the thermal evaporation mechanism works. At higher laser fluences it has been found that a combination of the proposed supercritical ablation mechanism with optical breakdown in the volume of the gas phase is more realistic. [ABSTRACT FROM AUTHOR]

We present a novel approach for recovery of the directional connectivity of a small oscillator network by means of the phase dynamics reconstruction from multivariate time series data. The main idea is to use a triplet analysis instead of the traditional pairwise one. Our technique reveals an effective phase connectivity which is generally not equivalent to a structural one. We demonstrate that by comparing the coupling functions from all possible triplets of oscillators, we are able to achieve in the reconstruction a good separation between existing and non-existing connections, and thus reliably reproduce the network structure. [ABSTRACT FROM AUTHOR]

The cross phase between radial velocity perturbation and poloidal velocity perturbation plays an important role in the radial distribution of Reynolds stress. Recently, a novel theory of cross-phase dynamics predicts that, depending on the strength of the E  ×  B shearing, the cross phase can stay in two different states: phase locked state(weak shear regime) and phase slipping state(strong shear regime). For the first time we divided Reynolds stress into three parts, turbulence fluctuation, cross phase and coherence between and , and studied their relative influences on Reynolds stress in different regimes. The profile of Reynolds stress and its three parts are measured separately by using multi-tipped Langmuir probe array. We observe that the three parts contribute to the radial distribution of Reynolds stress differently. In strong shear layer, the cross phase is randomly scattered across the layer—a signature of incoherent phase slips. Correspondingly, the radial distribution of the Reynolds stress is determined by the cross phase dynamics. In the weak shear region, the cross phase tends to stay in a coherent state (i.e. the phase locked state), where the turbulence fluctuation and coherence play a more important role. Besides, a direct relation between the coherence and the cross phase scattering is observed. Once the scattering of the cross phase increases, the coherence decreases. [ABSTRACT FROM AUTHOR]

To reveal the dynamic mechanism underlying Parkinsonian resting tremor, we applied a phase dynamics modelling technique to local field potentials and accelerometer signals recorded in three Parkinsonian patients with implanted depth electrodes. We detect a bidirectional coupling between the subcortical oscillation and the tremor. The tremor - brain driving is a linear effect with a small delay corresponding to the neural transmission time. In contrast, the brain - tremor driving is a nonlinear effect with a long delay in the order of 1-2 mean tremor periods. Our results are well reproduced for an ensemble of 41 tremor epochs in three Parkinsonian patients and confirmed by surrogate data tests and model simulations. The uncovered mechanism of tremor generation suggests to specifically counteract tremor by desynchronizing the subcortical oscillatory neural activity. [ABSTRACT FROM AUTHOR]

Mixed quantum–classical spin systems have been proposed in spin chain theory and, more recently, in magnon spintronics. However, current models of quantum–classical dynamics beyond mean-field approximations typically suffer from long-standing consistency issues, and, in some cases, invalidate Heisenberg's uncertainty principle. Here, we present a fully Hamiltonian theory of quantum–classical spin dynamics that appears to be the first to ensure an entire series of consistency properties, including positivity of both the classical and the quantum density, so that Heisenberg's principle is satisfied at all times. We show how this theory may connect to recent energy-balance considerations in measurement theory and we present its Poisson bracket structure explicitly. After focusing on the simpler case of a classical Bloch vector interacting with a quantum spin observable, we illustrate the extension of the model to systems with several spins, and restore the presence of orbital degrees of freedom. [ABSTRACT FROM AUTHOR]

Objective. A data-driven technique for parsimonious modeling and analysis of dynamic cerebral autoregulation (DCA) is developed based on the concept of diffusion maps. Specifically, first, a state-space description of DCA dynamics is considered based on arterial blood pressure, cerebral blood flow velocity, and their time derivatives. Next, an eigenvalue analysis of the Markov matrix of a random walk on a graph over the dataset domain yields a low-dimensional representation of the intrinsic dynamics. Further dimension reduction is made possible by accounting only for the two most significant eigenvalues. The value of their ratio indicates whether the underlying system is governed by active or hypoactive dynamics, indicating healthy or impaired DCA function, respectively. We assessed the reliability of the technique by considering healthy individuals and patients with unilateral internal carotid artery (ICA) stenosis or occlusion. We computed the sensitivity of the technique to detect the presumed side-to-side difference in the DCA function of the second group (assuming hypoactive dynamics on the occluded or stenotic side), using McNemar's chi square test. The results were compared with transfer function analysis (TFA). The performance of the two methods was also compared under the assumption of missing data. Main results. Both diffusion maps and TFA suggested a physiological side-to-side difference in the DCA of ICA stenosis or occlusion patients with a sensitivity of 81% and 71%, respectively. Further, both two methods suggested the difference between the occluded or stenotic side and any two sides of the healthy group. However, the diffusion maps captured additional difference between the unoccluded side and the healthy group, that TFA did not. Furthermore, compared to TFA, diffusion maps exhibited superior performance when subject to missing data. Significance. The eigenvalues ratio derived using the diffusion maps technique can be potentially used as a reliable and robust biomarker for assessing how active the intrinsic dynamics of the autoregulation is and for indicating healthy versus impaired DCA function. [ABSTRACT FROM AUTHOR]

This tutorial introduces the theoretical and experimental basics of electromagnetically induced transparency (EIT) in thermal alkali vapors. We first give a brief phenomenological description of EIT in simple three-level systems of stationary atoms and derive analytical expressions for optical absorption and dispersion under EIT conditions. Then we focus on how the thermal motion of atoms affects various parameters of the EIT system. Specifically, we analyze the Doppler broadening of optical transitions, ballistic versus diffusive atomic motion in a limited-volume interaction region, and collisional depopulation and decoherence. Finally, we discuss the common trade-offs important for optimizing an EIT experiment and give a brief 'walk-through' of a typical EIT experimental setup. We conclude with a brief overview of current and potential EIT applications. [ABSTRACT FROM AUTHOR]

We analyze the circumgalactic medium (CGM) for eight commonly-used cosmological codes in the AGORA collaboration. The codes are calibrated to use identical initial conditions, cosmology, heating and cooling, and star formation thresholds, but each evolves with its own unique code architecture and stellar feedback implementation. Here, we analyze the results of these simulations in terms of the structure, composition, and phase dynamics of the CGM. We show properties such as metal distribution, ionization levels, and kinematics are effective tracers of the effects of the different code feedback and implementation methods, and as such they can be highly divergent between simulations. This is merely a fiducial set of models, against which we will in the future compare multiple feedback recipes for each code. Nevertheless, we find that the large parameter space these simulations establish can help disentangle the different variables that affect observable quantities in the CGM, e.g., showing that abundances for ions with higher ionization energy are more strongly determined by the simulation’s metallicity, while abundances for ions with lower ionization energy are more strongly determined by the gas density and temperature.

There are still essential aspects regarding cathodes requiring a comprehensive understanding. These include identifying the underlying phenomena that prevent reaching the theoretical capacity, explaining irreversible losses, and determining the cut-off potentials at which batteries should be cycled. We address these inquiries by investigating the cell’s capacity and phase dynamics by looking into the transport properties of electrons. This approach underlines the crucial role of electrons in influencing battery performance, similar to their significance in other materials and devices such as transistors, thermoelectrics, or superconductors. We use lithium iron phosphate LFP as a case study to demonstrate that understanding the electrochemical cycling behavior of a battery cell, particularly a Li//LFP configuration, hinges on factors like the total local potentials used to calculate chemical potentials, electronic density of states (DOS), and charge carrier densities. Our findings reveal that the stable plateau potential difference is 3.42 V, with maximum charge and minimum discharge potentials at 4.12 V and 2.80 V, respectively. The study illustrates the dynamic formation of metastable phases at a plateau voltage exceeding 3.52 V. Moreover, we establish that determining the working chemical potentials of elements like Li and Al can be achieved by combining their workfunction and DOS analysis. Additionally, we shed light on the role of carbon black beyond conductivity enhancement. Through Density functional theory (DFT) calculations and experimental methods involving scanning Kelvin probe (SKP) and electrochemical analysis, we comprehensively examine various materials, including Li, C, Al, Cu, LFP, FePO _4 , Li _0.25 FePO _4 , polyvinylidene fluoride, and Li _6 PS _5 Cl. The insights derived from this study, which solely rely on electrical properties, have broad applicability to all cathodes and batteries. They provide valuable information for efficiently selecting optimal formulations and conditions for cycling batteries.

We propose a mean-field approach to describe the fluxoid dependence of magnetoresistance oscillations measured on two YBa2Cu3O7−x (YBCO) nanorings. We unveil the relation between the quantum interference processes and current localization phenomena in superconductor nanorings, which are non-ideal because of the presence of stubs. The model, based on the change in supercurrent transmission due to fluxoid dynamics, provides a dependence of the measured differential voltage on the external magnetic field. In particular, the signature of the Little and Parks (LP) effect results from phase dynamics involving the transmission of probe currents crossing the ring, while magnetoresistance background is related to the screening currents dynamics driven by vortex nucleation. The model allows for tracing out the entire magnetoresistance, which is the result of the superposition of single vortex-like topological defects involving current localization. This approach provides a new conceptual frame to explain the LP effect that does not invoke the lowering of superconducting stiffness. [ABSTRACT FROM AUTHOR]

We present a theoretical study of resonant frequencies and spatial correlations of Josephson phases in frustrated arrays of Josephson junctions. Two types of one-dimensional arrays, namely, the diamond and sawtooth chains, are discussed in detail. For these arrays in the linear regime the Josephson phase dynamics is characterized by multiband dispersion relation , and the lowest band becomes completely flat at a critical value of frustration, f   =  f c. In a strongly nonlinear regime such critical value of frustration determines the crossover from non-frustrated (0  <  f   <  f c) to frustrated (f c  <  f   <  1) regimes. The crossover is characterized by the thermodynamic spatial correlation functions of phases on vertices, , i.e. displaying the transition from long- to short-range spatial correlations. We find that higher-order correlations functions, e.g. p   =  2 and p   =  3, restore the long-range behavior deeply in the frustrated regime, . Monte-Carlo simulations of the thermodynamics of frustrated arrays of Josephson junctions are in good agreement with analytical results. We also outline the extension of our results to the case of kagome lattice, prototypical 2D frustrated lattice, and other higher dimensional lattices. [ABSTRACT FROM AUTHOR]