Bi2Se3 nanocrystals with various morphologies, including nanotower, nanoplate, nanoflake, nanobeam and nanowire, have been synthesized. Well-distinguished Shubnikov-de Haas (SdH) oscillations were observed in nanoplates nanobeams. Careful analysis of the SdH suggests existence Berry's phase π, which confirms quantum transport surface Dirac fermions both nanobeams without intended doping. The observation singular topological states implies that high-quality nanostructures superiorities for...

The photothermoelectric effect in topological insulator Bi2Se3 nanoribbons is studied. surface states are excited to be spin-polarized by circularly polarized light. Because the direction of electron spin locked its momentum for spin-helical states, significantly enhanced as oriented motions spins accelerated temperature gradient. results explained based on microscopic mechanisms a photon induced transition from Dirac cone bulk conduction band. as-reported expected have potential...

We report the magnetotransport properties of individual Bi2Se3 nanoplates. The carrier Hall mobility is up to 104 cm2/Vs. A large positive linear magnetoresistance (MR) approaching 400% without sign saturation was observed at 14 T. By angular dependence measurements, we demonstrate that MR originates from a two-dimensional transport. Furthermore, by comparing and longitudinal resistance under different temperatures, give very clear evidence reveals close relationship between mobility.

We propose a magnetic and electric level spin-transfer torque random access memory (STT-RAM) cell model to simulate the write operation of an STT-RAM. The tunneling junction (MTJ) is modified take into account electrical response MOS transistor that connected MTJ. A dynamic design flow also proposed minimize any unnecessary margin in STT-RAM by leveraging from new model. with one-transistor-one-MTJ (1T1J) structure shows our technique can reduce more than 22% area, compared conventional at...

Dirac-like surface states on surfaces of topological insulators have a chiral spin structure with locked to momentum, which is interesting in physics and may also important applications spintronics. In this work, by measuring the tunable helicity-dependent photocurrent (HDP), we present an identification HDP from at room temperature. It turns out that total has two components, one states, other accumulation layer. These components opposite directions. The clear gate tuning electron density...

Evident spin valve signals are observed in Co/graphene/Co sandwich structures with both monolayer and two-layer graphene stacks at temperatures from 1.5 K to 300 K. All the devices demonstrate linear current–voltage curves, indicating that an Ohmic property is dominating rather than a tunneling effect. The vertical valves have potential applications high-density non-volatile memories.

Magnetotransport measurements of topological insulators are very important to reveal the exotic surface states for spintronic applications. However, novel properties related Dirac fermions usually accompanied by a large linear magnetoresistance under perpendicular magnetic field, which makes identification obscure. Here, we report prominent Shubnikov-de Haas (SdH) oscillations an in-plane identified originate from in sidewalls insulator Bi2Se3 nanoplates. Importantly, SdH appear with...

Topological insulators have exotic surface states that are massless Dirac fermions, manifesting special magnetotransport properties, such as the Aharonov–Bohm effect, Shubnikov–de Haas oscillations, and weak antilocalization effects. In cone, band structures typically closely related to p-orbitals possess helical orbital texture. Here we report on tunability of transport properties via interaction between magnetic field spin–orbital angular momentum in individual Bi2Se3 nanoribbons. Because...

Graphene-based vertical heterostructures, particularly stacks incorporated with other layered materials, are promising for nanoelectronics. The stacking of two model Dirac graphene and topological insulator, can considerably enlarge the family van der Waals heterostructures. Despite well understanding individual electron transport properties a combined heterojunction still unknown. Here we show experimental realization between Bi2Se3 nanoplate monolayer graphene. At low temperatures, through...

This paper presents the optimal design methodology of number and locations actuators in active vibration control a space truss using multiple piezoelectric ceramic stack actuators. The eigenvalue distribution energy correlative matrix input force is applied to determine required, genetic algorithms (GAs) are adopted search for results show that disturbance acting on structure key factor determining structural control, global efficient optimization solution actuator can be obtained GAs.

High quality Bi2Se3 nanoflake arrays with a large area and high-yield production have been fabricated by chemical vapor deposition. As the essential candidate for topological insulator, unique surface electronic states are considered to play crucial role distinct from bulk. Our experimental results show that environmental doping significantly affects field emission properties of synthesized arrays. X-ray photoelectron spectroscopy characterizations indicate rapid oxidation may prohibit...

Strain is an important method to tune the properties of topological insulators. For example, compressive strain can induce superconductivity in Bi2Se3 bulk material. Topological insulator nanostructures are superior candidates utilize unique surface states due large volume ratio. Therefore, it highly desirable monitor local effects individual nanostructures. Here, we report systematical micro-Raman spectra single strained nanoribbons with different thicknesses and facets, where four optical...

The mechanical properties of polyurethane grouting materials were significantly improved when cement, sodium meta-silicate, red mud, slag, and fly ash added. However, the mechanisms composite are not clear. in asphalt pavement subsidence investigated. results computed tomography analysis show that foam is filled with geopolymer hydration products. from ground penetrating radar after mapping has no significant fluctuation or dislocation effect, which indicates effect strong. high-density...

Abstract The peculiar defect‐related photon emission processes in 2D hexagonal boron nitride (hBN) have become a topic of intense research due to their potential applications quantum information and sensing technologies. Here, it is reported on exotic single photons enhanced deep‐level emissions hBN strain crystal, which fabricated by transferring multilayer onto close‐packed silica spheres substrate. Effective activation realized from the defect ensembles at positions that are contact with...

In this work, to analyse the changing characteristics of contact stresses in tyre–pavement interface and functional relationship between rolling resistance working conditions truck-bus tyres, a three-dimensional model is established used predict distribution under different tyre, comprising various tyre loads, inflation pressures, velocities. Results show that magnitude transverse longitudinal related conditions, overload low pressure are important contributors wear shoulder. addition,...

High-content waste-rubber-modified asphalt (HRMA) has high viscosity and poor storage stability. HRMA not only improves the properties of road asphalt, but also reduces environmental pollution caused by waste tires. Enhancing molecular interaction rubber is key to making full use HRMA. In this paper, aromatic oil was used as activator for rubber. The mechanism between investigated. radial distribution function, diffusion coefficient, free volume, solubility parameter, shear were calculated...

Based on attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and principal component analysis (PCA), four kinds of asphalt (two matrix asphalts, TPC70# JL70# two modified SBS-1 SBS-2) were aged using the rolling thin-film oven test (RTFOT). The multiple stress repeated creep recovery (MSCR) was carried out an AR1500ex dynamic shear rheometer (DSR). PCA spectrum a pretreated asphalt, factors (oxidation factor change factor) determined, comprehensive index F...

It has recently been predicted that the surface plasmons are allowed to exist on interface between a topological insulator and vacuum. Surface can be employed enhance optical emission from various illuminants. Here, we study photoluminescence properties of ZnO/Bi2Te3 hybrid structures. Thin flakes Bi2Te3, typical three-dimensional insulator, were prepared ZnO crystal by mechanical exfoliation method. The ultraviolet was found enhanced Bi2Te3 thin flakes, which attributed plasmon – photon...

The introduction of a multi-jet structure at the bottom and middle fluidized bed can intensify interphase mixing improve desulfurization efficiency. computational fluid dynamics were used to study gas-liquid-solid flow in (BMJFB MMJFB). It was found that for mixing, intensification effect introducing is more obvious than bottom. water spray volume rate on MMJFB examined under same conditions. results showed with increase rate, process are promoted MMJFB, its efficiency reaches 68.2%. effects...

Abstract Regulating the electronic structures and carrier dynamics in 2D materials via elastic strain is a fascinating avenue for tailoring their optoelectronic properties at atomic scale. Here, abnormal response of indirect excitons to non‐uniform MoS 2 flakes reported. The introduced by transferring them pre‐prepared convex cross on SiO /Si substrate, where topography distribution are determined force microscopy Raman spectroscopy, respectively. It observed that emission energy shows an...

We report a gate-voltage modulation on the weak anti-localization of individual topological insulator Bi2Se3 nanoribbons. The phase coherence length decreases with decreasing carrier density surface states bottom nanoribbon as tuning gate voltage from 0 to −100 V, indicating that electron-electron interaction dominates decoherence at low density. Furthermore, we observe an abnormal conductance decline positive regime, which is ascribed capture carriers by trapping centers in oxidation layer.

Electrical spin injection into and extraction from a wide-bandgap semiconductor SiC at room temperature were demonstrated via Schottky junctions. The relaxation time of could reach 300 ps, overwhelming that Si with similar carrier density due to the smaller atomic number. We also found there existed two channels in SiC/CoFeB junctions for relaxation, one bulk other interfacial defect states within barrier whose times about 1 ns. bias condition controlled transport or then affected effective...