Linear Potential Research Articles

Time-dependent wave packet’s dynamics of a particle confined in the linear potential

Time-dependent wave packet’s dynamics of a particle confined in the linear potential

Cosmic clues: DESI, dark energy, and the cosmological constant problem

Several attempts to solve the cosmological constant problem, which concerns the value of the cosmological constant being extremely smaller than the Standard Model mass scales, have introduced a scalar field with a very flat potential that can be approximated as linear around any given position. The scalar field scans the cosmological constant in such a way that the current small value is explained. Recently, Dark Energy Spectroscopic Instrument (DESI) reported the results of the first year. Combining the data with CMB, Pantheon, Union3, and/or DES-SN5YR, there is a preference or anomaly, indicating that the dark energy in the current Universe slightly deviates from that in the ΛCDM model and varies over time. In this paper, I show that the simple linear potential of a scalar field that may explain the small cosmological constant, can explain the DESI anomaly. The conclusions do not change by including or not including a thermal friction effect. In particular, the model proposed by the present author in [1], which relaxes the cosmological constant by the condition that inflation ends, predicts a time-dependence of the dark energy close to the one favored by the data.

Charged scalar bosons in a Bonnor–Melvin-Λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varLambda $$\\end{document} universe at conical approximation

The quantum dynamics of charged scalar bosons in a Bonnor–Melvin-Λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varLambda $$\\end{document} universe is considered. In this study, the behavior of charged scalar bosons is explored within the framework of the Duffin–Kemmer–Petiau (DKP) formalism. Adopting a conical approximation (Λ≪1),\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(\\varLambda \\ll 1),$$\\end{document} we are considered two scenarios for the vector potential: a linear and quadratic vector potentials. In particular, the effects of this background in the equation of motion, phase shift, S-matrix, energy spectrum and DKP spinor are analyzed and discussed.

Phase-space analysis in non-minimal symmetric-teleparallel dark energy

We modify the symmetric-teleparallel dark energy through the addition of a further Yukawa-like term, in which the non-metricity scalar, Q, is non-minimally coupled to a scalar field Lagrangian where the phion acts as quintessence, describing dark energy. We investigate regions of stability and find late-time attractors. To do so, we conduct a stability analysis for different types of physical potentials describing dark energy, namely the power-law, inverse power-law, and exponential potentials. Within these choices, we furthermore single out particular limiting cases, such as the constant, linear and inverse potentials. For all the considered scenarios, regions of stability are calculated in terms of the signs of the coupling constant and the exponent, revealing a clear degeneracy among coefficients necessary to ensure stability. We find that a generic power-law potential with α>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha > 0$$\\end{document} is not suitable as a non-minimal quintessence potential and we put severe limits on the use of inverse potential, as well. In addition, the equations of state of each potential have been also computed. We find the constant potential seems to be favored than other treatments, since the critical point appears independent of the non-minimal coupling.

Understanding the corrosion and structural potential of 95Al-RHA-PSA composite for advance application

Material reinforcement has become popular in improving properties, such as corrosion, mechanical and wear behaviour. Aluminium-base composite has found usefulness in the technology of automobiles, aerospace, and marine and designs of a wide range of components. The use of reinforcement materials increases the efficiency of composites products and reduces overall expenses. Aluminium alloy composite provides low-cost advantages over many other matrix composites. The use of agro-based waste material as reinforcement alternatives is becoming very important because of its close to nothing cost and availability to produce nanoparticles. This study aim to use agro based processed rice hulls (RHA) and periwinkle shells (PSA) to improve aluminium properties in an attempt to gain prominence in today's automotive advancements. SEM imaging was conducted at a magnification of 15,000 at 20 kV to evaluate structural properties, while X-ray Diffractometer (XRD) images were utilized to observe the crystallography peaks and phases of the developed alloys. Rockwell hardness testing, in accordance with ASTM E18 standards, involved subjecting the samples to a 30 kg/f load for 30 s using a hardened steel ball for indentation. Corrosion properties were assessed via linear polarization resistance and open circuit potential measurements. From the results, there is a higher corrosion resistance from 95Al-RHA-PSA composite samples compared to the control (aluminium alloy) samples. The lower values of jcorr and higher values of Pr of the 95Al-RHA-PSA composite samples also indicated that the RHA and PSA content of the composite minimized the penetration of chloride ions into the active sites of the composite samples. The 95Al-2RHA-3PSA composite sample exhibited the lowest Cr of 1.4172 mm/year, lowest jcorr of 1.220E-04 A/cm2 and highest Pr of 70.02 Ω, which indicated the 95Al-2RHA-3PSA composite sample provided the most significant passivation, leading higher corrosion resistance. The XRD of the control sample has several crystallographic phases, with AlNi3Al2SiO8 exhibiting the most elevated peak intensity at about 550 a.u (2θ = 39°). In comparison, the peak intensity of the other crystals is less than 200 a.u. However, the 95Al-RHA-PSA composite samples exhibited crystallites of higher peak intensities and better morphological strengthening characteristics. The findings suggest promising prospects for the development of sustainable and long-lasting aluminium alloy for automotive use.

Proper orthogonal descriptors for multi-element chemical systems

We introduce the proper orthogonal descriptors for efficient and accurate interatomic potentials of multi-element chemical systems. The potential energy surface of a multi-element system is represented as a many-body expansion of parametrized potentials which are functions of atom positions, atom types, and parameters. The proper orthogonal decomposition is employed to decompose the parametrized potentials as a linear combination of orthogonal basis functions. The orthogonal basis functions are used to construct proper orthogonal descriptors based on the elements of atoms, thus leading to multi-element descriptors. We compose the multi-element proper orthogonal descriptors to develop linear and quadratic interatomic potentials. We devise an algorithm to efficiently compute the total energy and forces of the interatomic potentials constructed from the proper orthogonal descriptors. The potentials are demonstrated for indium phosphide and titanium dioxide in comparison with the spectral neighbor analysis potential (SNAP) and atomic cluster expansion (ACE) potentials.

Towards the Analytical Generalization of the Transcendental Energy Equation, Group Velocity, and Effective Mass in One-Dimensional Periodic Potential Wells with a Computational Application to Common Coupled Potentials

The analytical generalization for N periodic potential wells coupled to a probe rectangular-like potential and a zero potential is extremely important in the study of one-dimensional periodic potentials in solid state physics, e.g., in the calculation of transport, optical, and magnetic properties. These findings raise the possibility of calculating equations for the generalization of N arbitrary potentials related to any potential V(x) using special functions as a solution. In this work, a novel analytical generalization of the transcendental energy equation, group velocity, and effective mass for N-coupled potentials to a probe one-dimensional potential V=V(x) was proposed. Initially, two well-known linear periodic potentials V=V(x) were employed to obtain analytical solutions for rectangular-like and Dirac-delta potentials. Python libraries were used to easily represent the equations for one or two rectangular-like potentials coupled with an arbitrary potential, highlighting the transcendental energy, group velocity, and effective mass. The results showed that the group velocity behavior changed its orientation due to the sign of the potential, whereas the width of the potential V(x) strongly influenced the group velocity behavior. The effective mass was also modified by the potential shapes, and their combinations, both effective mass and group velocity, exhibited similar physical behaviors to those found in ordinary rectangular-like potentials.

New potentiometric sensor for total phenolic assay of plant extracts

Abstract In this study, a sensitive, fast, and inexpensive new potentiometric determination method based on the Folin–Ciocalteu reagent (FCR) is proposed to determine the total phenolic content in plant extracts. For this purpose, a potentiometric-based all-solid-state-contact polyvinyl chloride membrane sensor was developed. Gallic acid compound was used as the active component (ionophore) in the developed sensor and the potentiometric behavior of the sensor was characterized. The detection limit of the selective sensor to the FCR was determined as 0.022 mol L−1 and showed a linear potential change in the concentration range of 0.0039 to 0.5 mol L−1 and a fast response time of 40 to 45 s. The developed sensor was also applied to the plant extracts and the obtained measurement results were found to be in agreement with the spectrometer results in the literature.

Spherical quantum dot described by a scalar exponential potential under the influence of a linear scalar potential and a global monopole

Based on the power-exponential potential, we study the confinement of a particle to a spherical quantum dot under the influence of a linear scalar potential. We show that the energy eigenvalues s-waves can be obtained from approximate solutions to the Schrödinger equation. Further, we consider the global monopole spacetime and study the topological effects of this spacetime background on the confinement of a particle to a spherical quantum dot under the influence of a linear scalar potential.

Optimized Fabrication of Carbon-Fiber Microbiosensors for Codetection of Glucose and Dopamine in Brain Tissue.

Dopamine (DA) signaling is critically important in striatal function, and this metabolically demanding process is fueled largely by glucose. However, DA and glucose are typically studied independently and, as such, the precise relationship between DA release and glucose availability remains unclear. Fast-scan cyclic voltammetry (FSCV) is commonly coupled with carbon-fiber microelectrodes to study DA transients. These microelectrodes can be modified with glucose oxidase (GOx) to generate microbiosensors capable of simultaneously quantifying real-time and physiologically relevant fluctuations of glucose, a nonelectrochemically active substrate, and DA, which is readily oxidized and reduced at the electrode surface. A chitosan hydrogel can be electrodeposited to entrap the oxidase enzyme on the sensor surface for stable, sensitive, and selective codetection of glucose and DA using FSCV. This strategy can also be used to entrap lactate oxidase on the carbon-fiber surface for codetection of lactate and DA. However, these custom probes are individually fabricated by hand, and performance is variable. This study characterizes the physical nature of the hydrogel and its effects on the acquired electrochemical data in the detection of glucose (2.6 mM) and DA (1 μM). The results demonstrate that the electrodeposition of the hydrogel membrane is improved using a linear potential sweep rather than a direct step to the target potential. Electrochemical impedance spectroscopy data relate information on the physical nature of the electrode/solution interface to the electrochemical performance of bare and enzyme-modified carbon-fiber microelectrodes. The electrodeposition waveform and scan rate were characterized for optimal membrane formation and performance. Finally, codetection of both DA/glucose and DA/lactate was demonstrated in intact rat striatum using probes fabricated according to the optimized protocol. Overall, this work improves the reliable fabrication of carbon-fiber microbiosensors for codetection of DA and important energetic substrates that are locally delivered to the recording site to meet metabolic demand.

Wave attenuation by three-dimensional circular floating sea ice: Regular and irregular waves

The evolution of ice conditions and wave patterns in polar water areas is complex, and studying the hydrodynamic response between sea ice and waves is crucial. In this study, the hydrodynamic response of sea ice in infinitely deep water is investigated by a sea ice scattering model based on linear potential flow and thin plate approximation theory. Building upon regular wave and sea ice scattering models, an irregular wave model was established and analyzed. This paper discusses the factors that influence sea ice resonance in a three-dimensional scattering model. It categorizes resonance phenomena into strong and weak based on mass and elasticity coefficients and provides a predictive function for identifying strong resonance points. Additionally, the study examines sea ice attenuation from an energy perspective. Research on sea ice in irregular waves indicates a negative correlation between the directional spreading parameter and wave attenuation. An increase in directional spreading parameter weakens the inhibitory effect on the high-frequency part of the waves. Increasing sea ice thickness enhances wave attenuation, exerting an inhibitory effect on waves in the high-frequency region.

On the Klein–Gordon oscillators in Eddington-inspired Born-Infeld gravity global monopole spacetime and a Wu–Yang magnetic monopole

We consider Klein–Gordon (KG) particles in a global monopole (GM) spacetime within Eddington-inspired Born–Infeld gravity (EiBI-gravity) and in a Wu–Yang magnetic monopole (WYMM). We discuss a set of KG-oscillators in such spacetime settings. We propose a textbook power series expansion for the KG radial wave function that allows us to retrieve the exact energy levels for KG-oscillators in a GM spacetime and a WYMM without EiBI-gravity. We, moreover, report some conditionally exact, closed form, energy levels (through some parametric correlations) for KG-oscillators in a GM spacetime and a WYMM within EiBI-gravity, and for massless KG-oscillators in a GM spacetime and a WYMM within EiBI-gravity under the influence of a Coulomb plus linear Lorentz scalar potential. We report the effects of the Eddington parameter κ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa $$\\end{document}, GM-parameter α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}, WYMM strength σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sigma $$\\end{document}, KG-oscillators’ frequency Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega $$\\end{document}, and the coupling parameters of the Coulomb plus linear Lorentz scalar potential, on the spectroscopic structure of the KG-oscillators at hand. Such effects are studied over a vast range of the radial quantum number nr≥0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n_r\\ge 0$$\\end{document} and include energy levels clustering at κ>>1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa>>1$$\\end{document} (i.e., extreme EiBI-gravity), and at |σ|>>1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$|\\sigma |>>1$$\\end{document} (i.e., extreme WYMM strength).

Preparation of Spherical δ-MnO2 Nanoflowers by One-Step Coprecipitation Method as Electrode Material for Supercapacitor.

Spherical δ-MnO2 nanoflower materials were synthesized via a facile one-step coprecipitation method through adjusting the molar ratio of KMnO4 to MnSO4. The influence of the molar ratio of the reactants on the crystal structure, morphology, and electrochemical performances was investigated. At a molar ratio of 3.3 for KMnO4 to MnSO4, the spherical δ-MnO2 nanoflowers composed of nanosheets with the highest specific surface area (228.0 m2 g-1) were obtained as electrode materials. In the conventional three-electrode system using 1 M Na2SO4 as an electrolyte, the specific capacitance of the spherical δ-MnO2 nanoflowers reached 172.3 F g-1 at a current density of 1 A g-1. Moreover, even after 5000 cycles at a current density of 5 A g-1, the GCD curves remained essentially unchanged, and the specific capacitance still retained 86.50% of the maximum value. The kinetics of the electrode reaction were preliminarily studied through the linear potential sweep technique to observe diffusion-controlled contribution toward total capacitance. For the spherical δ-MnO2 nanoflower electrode material, diffusion-controlled contribution accounted for 65.1% at low scan rates and still remained significant at high scan rates (100 mV s-1), indicating excellent utilization efficiency of the bulk phase. The as-fabricated asymmetric supercapacitor HFC-7//MnO2-3.3-ASC presented a prominent specific energy of 16.5 Wh kg-1 at the specific power of 450 W kg-1. Even when the specific power reached 9.0 kW kg-1, the energy density still retained 9.5 Wh kg-1.

Hydrodynamic performance of vertical cylindrical wave energy absorbers in front of a vertical wall

This paper studies the hydrodynamic performance of vertical cylindrical absorbers in front of a vertical wall. All the absorbers are independent of each other and restricted to only the heave motion. Based on a linear potential flow theory, an analytical solution is developed for the problems of wave diffraction and radiation by absorbers. In the solving procedure, the hydrodynamic problem is first transformed into an equivalent problem in an open water domain using the image principle. The number of absorbers in the equivalent problem is twice that in the real problem, and the plane layout is symmetric about the original vertical wall. The velocity potential of the fluid domain is obtained using the method of variable separation, and the unknown expansion coefficients in the velocity potential are determined by the matched boundary conditions. The heave excitation force, added mass, radiation damping, motion response, and energy capture width of the absorbers are calculated. Case studies are presented to show the effects of the wall reflection and hydrodynamic interaction on the energy extraction performance of the wave energy converter (WEC) system. Subsequently, the WEC performance under the action of irregular waves is analyzed by considering an incident wave spectrum, and the mean annual absorbed power of the device is estimated by considering the wave data statistics at the actual sites. The results indicate that when the wave motion resonates with the absorber motion, the energy extraction performance of the absorbers is significantly improved. The performance of the absorbers can be effectively improved when the structures are close to the antinodes of a standing wave field. By designing a reasonable plane layout, the hydrodynamic interaction can play a constructive role in the performance of the WEC system.

Optimization Analysis of the Shape and Position of a Submerged Breakwater for Improving Floating Body Stability

Submerged breakwaters can be installed underneath floating structures to reduce the external wave loads acting on the structure. The objective of this study was to establish an optimization analysis framework to determine the corresponding shape and position of the submerged breakwater that can minimize or maximize the external forces acting on the floating structure. A two-dimensional frequency-domain boundary element method (FD-BEM) based on the linear potential theory was developed to perform the hydrodynamic analysis. A metaheuristic algorithm, the advanced particle swarm optimization, was newly coupled to the FD-BEM to perform the optimization analysis. The optimization analysis process was performed by calling FD-BEM for each generation, performing a numerical analysis of the design variables of each particle, and updating the design variables using the collected results. The results of the optimization analysis showed that the height of the submerged breakwater has a significant effect on the surface piercing body and that there is a specific area and position with an optimal value. In this study, the optimal values of the shape and position of a single submerged breakwater were determined and analyzed so that the external force acting on a surface piercing body was minimum or maximum.

Embeddable Chloride Sensor for Monitoring Chloride Penetration into Cement Mortar.

A composite solid chloride sensor consisting of two single sensors, i.e., Ag/AgCl working electrode and Mn/MnO2 reference electrode, was developed. The Ag/AgCl electrode was prepared by the anodic polarization method, while the Mn/MnO2 reference electrode was prepared using the powder compaction technique. Then, the electrochemical performances such as stability, reproducibility, and sensitivity of the composite and single sensors were investigated in a saturated Ca(OH)2 solution and mortar specimen. A current density of 0.5 mA/cm2 and polarization time of 2.5 h were the optimal preparation parameters of the Ag/AgCl selective electrode. The Ag/AgCl selective electrode showed a linear potential response with the logarithm of chloride ion content in solution and had good stability, reproducibility, and anti-polarization performances. In addition, the Mn/MnO2 electrode exhibited potential stability after being activated in an alkaline solution for 60 days. The composite sensor demonstrated exceptional sensitivity to the Cl- content, boasting a slope of approximately 51.1 mV/decade, and showcased excellent stability in both solution and mortar specimens. In every measurement, the time needed for the potential of a composite sensor to become stable was less than 30 s. The sensor enables non-destructive in situ monitoring of the chloride ion content in cement mortar, thus realizing early warning of deterioration of reinforcement and guaranteeing long service life of the structure.

Ring-like partially nonlocal extreme wave of a (3+1)-dimensional NLS system with partially nonlocal nonlinearity and external potential

This paper aims to study extreme waves localized in (3+1)-dimensional space based on a (3+1)-dimensional nonautonomous partially nonlocal NLS system under the linear and parabolic potentials, which is simplified into a (2+1)-dimensional autonomous equation via a converting formula. Based on solutions of the autonomous NLS system, an approximate solution of ring-like extreme wave is found. Characteristics and evolution of ring-like extreme wave are explored in an exponential system. The influence of the magnitude and exponential parameters of diffraction on ring-like extreme wave is studied. Moreover, the impact of the Hermite polynomial parameter q, the radius parameter R and the thickness parameter w on ring-like extreme wave is also discussed.

Color confinement and random matrices. A random walk down group manifold toward Casimir scaling

We explain the microscopic origin of linear confinement potential with the Casimir scaling in generic confining gauge theories. In the low-temperature regime of confining gauge theories such as QCD, Polyakov lines are slowly varying Haar random modulo exponentially small corrections with respect to the inverse temperature, as shown by one of the authors (M. H.) and Watanabe. With exact Haar randomness, computation of the two-point correlator of Polyakov loops reduces to the problem of random walk on group manifold. Linear confinement potential with approximate Casimir scaling except at short distances follows naturally from slowly varying Haar randomness. With exponentially small corrections to Haar randomness, string breaking and loss of Casimir scaling at long distance follow. Hence we obtain the Casimir scaling which is only approximate and holds only at intermediate distance, which is precisely needed to explain the results of lattice simulations. For (1 + 1)-dimensional theories, there is a simplification that admits the Casimir scaling at short distances as well.

Evidence of transient potentials in ion-selective electrodes based on thin-layer ion-exchange membranes

Polymeric membranes with ion-exchange properties have found numerous applications in water treatment, dialysis, energy storage, chemical sensors, and bio-interfaces, among others. Notably, it is common to operate under non-equilibrium conditions while pursuing specific features (e.g., current generation) through an electron-to-ion mechanism. To maximize the final performance, it is crucial to understand the role of each interface within the system, which becomes complex when the device is tailored with several materials and films. This is the case for ion sensors based on thin membranes in backside contact with a redox active conducting polymer. Herein, we investigate such a system operating under a charge transfer mechanism, which features electroneutrality maintenance as the main driving force upon application of a linear sweep potential. This potential is modeled as being unequally distributed among the various system interfaces. Our results demonstrate and quantify the existence of a transient membrane potential at the membrane-electrolyte interface, owing to the implementation of a strategical measurement point on the buried membrane side and connected to a built-in electrometer for the exclusive acquisition of the potential difference at such an interface. The transient membrane potential was found to be <1 % of the total applied potential, meaning that the ion-transfer process at the electrolyte-membrane interface is less energetically costly that the electron transfer and doping processes occurring at the conducting polymer side. This small contribution can be potentiated by increasing the ion-exchange capacity of the membrane, which indirectly enlarges the system current and serves as a strategy for increasing the efficiency of the device.

Extreme single-excitation subradiance from two-band Bloch oscillations in atomic arrays

Atomic arrays provide an important quantum optical platform with photon-mediated dipole–dipole interactions that can be engineered to realize key applications in quantum information processing. A major obstacle for such applications is the fast decay of the excited states. By controlling two-band Bloch oscillations of single excitation in an atomic array under an external magnetic field, here we show that exotic subradiance can be realized and maintained with orders of magnitude longer than the spontaneous decay time in atomic arrays with the finite size. The key finding is to show a way for preventing the wavepacket of excited states scattering into the dissipative zone inside the free space light cone, which therefore leads to the excitation staying at a subradiant state for an extremely long decay time. We show that such operation can be achieved by introducing a spatially linear potential from the external magnetic field in the atomic arrays and then manipulating interconnected two-band Bloch oscillations along opposite directions. Our results also point out the possibility of controllable switching between superradiant and subradiant states, which leads to potential applications in quantum storage.