黄平 Huang Ping

Xi'an Jiaotong University | XJTU

The electric transport properties of diazonium functionalized graphene (DFG) were investigated. The temperature dependence of the resistivity (ρ-T) and the Shubnikov-de Haas oscillation of the DFG revealed two-dimensional hole gas (2DHG) behaviors. The DFGs exhibited unusual weak localization behaviors in which both inelastic and chirality-breaking...

The unique honeycomb lattice structure of graphene gives rise to its outstanding electronic properties such as ultrahigh carrier mobility, ballistic transport, and more. However, a crucial obstacle to its use in the electronics industry is its lack of an energy bandgap. A covalent chemistry strategy could overcome this problem, and would have the b...

Uniquely in Cu2OSeO3 , the Skyrmions, which are topologically protected magnetic spin vortexlike objects, display a magnetoelectric coupling and can be manipulated by externally applied electric (E) fields. Here, we explore the E-field coupling to the magnetoelectric Skyrmion lattice phase, and study the response using neutron scattering. Giant E-f...

Exploiting additional degrees of freedom in solid state materials may be the most promising solution when approaching the quantum limit of the Moore's law for the conventional electronic industry. Recently discovered topologically non-trivial spin textures, skyrmions, are outstanding among such possibilities. However, controlled creation of skyrmio...

The phase transition most commonly observed is probably melting, a transition from ordered crystalline solids to disordered isotropic liquids. In three dimensions, melting is a single, first-order phase transition. In two-dimensional systems, however, theory predicts a general scenario of two continuous phase transitions separated by an intermediat...

We present a method to directly visualise a statistical analysis of skyrmion defect alignment at grain boundaries in the skyrmion host $$\hbox {Cu}_2$$ Cu 2 OSeO 3 . Using Lorentz transmission electron microscopy, we collected large data sets with several hundreds of frames containing skyrmion lattices with grain boundaries in them. To address the...

Skyrmions are chiral magnetic textures with non-trivial topology, and due to their unique properties they are widely considered as promising information carriers in novel magnetic storage applications. While electric field writing/erasing and manipulation of skyrmions have been recently achieved, quantitative insights into the energetics of those p...

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Chiral magnetic textures with non-trivial topology are known as skyrmions, and due to their unique properties they are promising in novel magnetic storage applications. While the electric manipulation of either isolated skyrmions or a whole skyrmion lattice have been intensively reported, the electric effects on skyrmion clusters remain scarce. In...

Investigating Skyrmions Using Lorentz Transmission Electron Microscopy - Volume 24 Supplement - Ping Huang, Rajeswari Jayaraman, Giulia Fulvia Mancini, Alex Kruchkov, Marco Cantoni, Yoshie Murooka, Tatiana Latychevskaia, Damien McGrouther, Edoardo Baldini, Jonathan Stuart White, Arnaud Magrez, Thierry Giamarchi, Fabrizio Carbone, Henrik Moodysson R...

Skyrmions are twirling magnetic textures whose non-trivial topology leads to particle-like properties promising for information technology applications. Perhaps the most important aspect of interacting particles is their ability to form thermodynamically distinct phases from gases and liquids to crystalline solids. Dilute gases of skyrmions have be...

Skyrmions are twirling magnetic textures whose non-trivial topology leads to particle-like properties promising for information technology applications. Perhaps the most important aspect of interacting particles is their ability to form thermodynamically distinct phases from gases and liquids to crystalline solids. Dilute gases of skyrmions have be...

We demonstrate that light-induced heat pulses of different duration and energy can write Skyrmions in a broad range of temperatures and magnetic field in FeGe. Using a combination of camera-rate and pump-probe cryo-Lorentz transmission electron microscopy, we directly resolve the spatiotemporal evolution of the magnetization ensuing optical excitat...

Magnetic skyrmions are localized nanometric spin textures with quantized winding numbers as the topological invariant. Rapidly increasing attention has been paid to the investigations of skyrmions since their experimental discovery in 2009, due both to the fundamental properties and the promising potential in spintronics based applications. However...

The creation, annihilation and motion of skyrmions in topological magnets offer interesting perspectives for data storage devices. The velocity of their appearance as well as their persistence range in the host material's phase diagram depend on the balance between thermodynamic and topological stability. Here, we demonstrate that individual laser...

Skyrmions are nanometric spin whirls that can be stabilized in magnets lacking inversion symmetry. The properties of isolated skyrmions embedded in a ferromagnetic background have been intensively studied. We show that single skyrmions and clusters of skyrmions can also form in the helical phase and investigate theoretically their energetics and dy...

We show that the observed ferromagnetic behavior of ZnO lightly doped with Mn coincides with the presence of MnO nanoparticles, whereas cluster-free Mn doped ZnO behaves paramagnetically. This conclusion is reached by a study of the structural and magnetic properties of powdered samples of (Mnx,Zn1–x)O with x ≤ 0.033 using polarized neutron scatter...

We have used inelastic neutron scattering to measure the magnetic excitation spectrum along the high-symmetry directions of the first Brillouin zone of the magnetic skyrmion hosting compound Cu2OSeO3. The majority of our scattering data are consistent with the expectations of a recently proposed model for the magnetic excitations in Cu2OSeO3, and w...

div class="title">Magnetic Dynamics Studied by Time-Resolved Electron Microscopy - Volume 21 Issue S3 - F. Carbone, R. Jayaraman, Y. Murooka, G.F. Mancini, E. Baldini, P. Huang, M. Cantoni, A. Magrez, D. McGrouther, T. Giamarchi, H. M. Rønnow

Significance The need for denser storage devices calls for new materials and nanostructures capable of confining single bits of information in a few nanometers. A new topological distribution of spins termed skyrmions is emerging, which promises to robustly confine a small magnetization in a few-nanometers-wide circular domain. A great deal of atte...

Small-angle diffraction of polarized neutrons and resonant contribution to diffraction of synchrotron radiation have been applied to prove chirality of the crystal and magnetic structures of the magnetoelectric insulator Cu2OSeO3. Similarly to other chiral magnets with P213 crystal structure the corresponding chiralities are linked to each other vi...

First-principles calculations (generalized gradient approximation, density functional therory (DFT) with dispersion corrections, and DFT plus local atomic potential) are carried out on the stability and electronic structures of superlattice configurations of nitrophenyl diazonium functionalized graphene with different coverage. In the calculations,...

Graphene sheets were successfully functionalized with 4-nitrophenyl diazonium (NPD). Two dimensional Raman analysis demonstrated that the reaction preferred to happen on single-layer graphene rather than bi-layer or multi-layer, and the edges of graphene were more reactive than the central areas. Atomic force microscopy (AFM) indicated the aryl gro...

Graphene functionalized via nitrophenyl groups covalently bonding to its basal plane is studied by Raman spectroscopy and electric transport measurements. The Raman spectra of functionalized graphene exhibit D mode and peaks derived from nitrophenyl groups, and the two fingerprints exhibit nearly the same distribution in the two-dimensional Raman m...

In this report, nanoprobes which could detect the femtogram level of arsenite ions in subcellular organelle of live cells are disclosed. The nanoprobes are composed of ssDNA and single-wall carbon nanotubes (SWCNTs), and the ssDNA is marked by a dye molecule. In a live cell, trace arsenite ions could interact with nanoprobes and significantly decre...

Polycrystalline NaCo 2 O 4−δ materials were prepared using the urea auto-combustion method. The reaction process and crystal growth were investigated through X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier transform infrared spectrometry (FTIR). The results indicate that the formation temperature of NaC...

The measurements of AC susceptibility between 2 and 40 K from zero field to 4 T both along the (0 0 1) and (1 1 1) axis in single-crystal Dy2Ti2O7 show that the spin freezing along the (1 1 1) axis has stronger frequency dependence and magnetic field dependence, and the starting freezing frequency of the single crystal is higher than that of the po...