A sustainable route from the biomass byproduct okara as a natural nitrogen fertilizer to high-content N-doped carbon sheets is demonstrated. The as-prepared unique structure exhibits high specific capacity (292 mAh g(-1) ) and extremely long cycle life (exceeding 2000 cycles). full battery devised for practical use of materials with flexible/wearable LED screen.

Based on the Landau-Lifshitz-Gilbert equation, it can be shown that a circularly polarized microwave reverse magnetization of Stoner particle through synchronization. In comparison with reversal induced by static magnetic field, when proper frequency is used minimal switching field much smaller than precessional reversal. A needs only to overcome energy dissipation in order magnetization, unlike conventional method where must anisotropy.

We report ultralong cycle-life lithium ion batteries based on nitrogen-doped graphene/MnO₂hybrids.

The magnetization reversal of Stoner particles is investigated from the point view nonlinear dynamics within Landau-Lifshitz-Gilbert formulation. following results are obtained. (1) We clarify that so-called Stoner-Wohlfarth (SW) limit becomes exact when damping constant infinitely large. Under limit, moves along steepest-energy-descent path. minimal switching field one at which there only stable fixed in system. (2) For a given magnetic anisotropy, critical value for constant, above same as...

The theoretical limit of the minimal magnetization switching field and optimal pulse design for uniaxial Stoner particles are investigated. Two results obtained. One is existence a smallest magnetic out all possible designs. It shown that proportional to damping constant in weak regime approaches Stoner-Wohlfarth (SW) at large damping. For realistic constant, this more than 10 times smaller so-called precessional reversal under noncollinear static field. other on design: if magnitude does...

For the ballistic quantum transport, conductance of each channel is quantized to a value ${2e}^{2}/h.$ In presence defects, electrons will be scattered such that deviate from values conductance. We show an antiresonance scattering can occur when extra defect level introduced into conduction band. At scattering, exactly one one-dimensional wire disappears, in good agreement with ab initio calculations. The takes nonzero Fermi energy away scattering.

We study the role of periodically driven time-dependent Rashba spin-orbit coupling (RSOC) on a monolayer graphene sample. After recasting originally $4\times 4$ system dynamical equations as two time-reversal related two-level problems, quasi-energy spectrum and dynamics are investigated via various techniques approximations. In static case is gapped at Dirac point. The rotating wave approximation (RWA) applied to unphysically preserves this feature, while Magnus-Floquet approach well...

Fast magnetization reversal of uniaxial Stoner particles by spin-transfer torque due to the spin-polarized electric current is investigated. It found that a with properly designed time-dependent polarization direction can dramatically reduce critical density required reverse magnetization. Under condition magnitude and degree do not vary time, shape optimal obtained such fastest.

A strategy is proposed aimed at substantially reducing the minimal magnetization switching field for a Stoner particle. Unlike normal method of applying static magnetic which must be larger than anisotropy, much weaker field, proportional to damping constant in weak regime, can used switch from one state another if along motion magnetization. The concept constantly supply energy particle time-dependent allow climb over potential barrier between initial and target states.

Proximity effect on field-effect characteristic (FEC) in double-wall carbon nanotubes (DWCNTs) is investigated. In a semiconductor-metal (S-M) DWCNT, the penetration of electron wavefunctions metallic shell to semiconducting turns original tube into metal with non-zero local density states at Fermi level. By using two-band tight-binding model ladder two legs, it demonstrated that anomalous FEC observed so-called S-M type DWCNTs can be fully understood by proximity phases.

We investigate field-driven domain wall (DW) propagation in magnetic nanowires the framework of Landau-Lifshitz-Gilbert equation. propose a new strategy to speed up DW motion uniaxial nanowire by using an optimal space-dependent field pulse synchronized with propagation. Depending on damping parameter, velocity can be increased about two orders magnitude compared standard case static uniform field. Moreover, under pulse, change total energy is proportional velocity, implying that rapid...

Stripy states, consisting of a collection stripy spin textures, are the precursors skyrmion crystals (SkXs). The common belief is that states and SkXs topologically unconnected transitions between phase transitions. Here, we show both condensates they equivalent. By gradually tuning stripe whose width goes from smaller than to larger skyrmion-skyrmion separation, structure condensate transforms smoothly continuously various phases, including helical mazes, crystals, showing connected SkXs.

The dependence of charges accumulated on a quantum dot under an external voltage bias is studied. charge sensitive to the changes number filled levels and conducting (channels). We clarify that there are two possible outcomes applying bias. (a) channels increases, but decreases. (b) increases or does not change while (levels) with In case (b), generally expected increase monotonically applied show, however, this expectation may materialize when electron transmission coefficients depend...

In this work, we demonstrate an approach to realize geometry-invariant multi-channel coherent perfect absorbers by embedding ultrathin conductive films in zero-index media. Coherent absorption can be achieved for waves incidents from arbitrary number of input channels as long the total width equals a critical value that is only determined length and material parameters instead their shapes positions. The attributes induced currents electric fields incidence, shape- position-independent...

The ac response of self-sustained current oscillations (SSCO's) in weakly coupled GaAs/AlAs superlattices (SL's) is derived based on the deformation a limit cycle under an external driving force. Frequency locking into integer fraction frequency obtained periodic which deforms either with or without topological change. This robust against bias because can adjust itself. results are verified both numerically and experimentally, indicating that SSCO's SL's be understood within framework...

We investigated the resonance and antiresonance effects in electronic transport through several-quantum-dot combinations by using nonequilibrium Green’s function method. All distinctive quantum-dot (QD) arrangements with one to three QDs different architectures were studied systematically. The theoretical numerical results show that a peak current-voltage spectrum can be attributed effect, whereas dip is due effect. will help experimenters better understand their measurements.

Current-driven DW motion in a ferrimagnetic (FiM) nanowire through spin transfer torques (STTs) is explained by the energy-work principle. An adiabatic STT (a-STT) can be incorporated into Lagrangian as an energy functional and tends to twist planes. DWs homogeneous FiM nanowires resist a-STT from moving below critical value proportional maximal transverse anisotropic field. Second, nonadiabatic (na-STT) cannot included enter dynamics Rayleigh functional. A static exist under na-STT such...

Abstract Field-driven domain wall (DW) motion in ferromagnetic nanowires with easy- and hard-axis anisotropies was studied theoretically numerically the presence of bulk Dzyaloshinskii-Moriya interaction (DMI) based on Landau-Lifshitz-Gilbert equation. We propose a new trial function offer an exact solution for DW along uniaxial nanowire driven by external magnetic field. A strategy suggested to speed up large DMI parameters. In anisotropy, we find that breakdown field velocity strongly...

Magnetically controlled zero-index metamaterials have numerous applications due to their wide tunable range and sensitive response bias magnetic field. In this paper, magnetically index-near-zero μ-near-zero based on ferrite been realized. Combining these proposed with proper waveguide structures, we obtained a structure structure, respectively. For both transmittance can be tuned by field in high sensitivity. Our metamaterial structures potential microwave devices such as switches, sensors...

The authors consider the traffic grooming problem on general topology WDM networks. is: given a set of t connections, their routes and factor g, find an optimal wavelength assignment such that number wavelengths required in network is minimised. This first formulated as integer linear programming problem, then heuristic proposed to solve it. simulation results show increasing can considerably decrease system.

One of the important issues in nanomagnetism is to lower current needed for a technologically useful domain wall (DW) propagation speed. Based on modified Landau-Lifshitz-Gilbert (LLG) equation with both Slonczewski spin-transfer torque and field-like torque, we derive optimal spin pattern fast DW along nanowires. Under such conditions, velocity biaxial wires can be enhanced as much ten times compared velocities achieved experiments so far. Moreover, variation polarization help depinning....

The connection between self-sustained current oscillations in superlattices and the famous van der Pol (vdP) equation is established by mapping a widely used model of to vdP equation. Since this can describe an inductor-capacitor-resistor circuit with nonlinear resistor negative differential conductance, we have obtained equivalent electric for oscillation regime. origin inductance superlattice revealed.

We propose a valve structure composed of zero-index metamaterial to manipulate the electromagnetic wave conveniently and effectively through regulating phase reflected waves. Both characteristics need not be changed when manipulating transmission, which maintains stability metamaterial. Moreover, good performance tuning is limited by shape size our proposed structure. By using structure, we demonstrate realization tunable curved anisotropic ε-near-zero material waveguide with irregular...