相关论文: First-principles study of native point defects in …
Density functional theory based First Principles calculations were used to study the effect of Silicon (Si) doping on the structural, electronic and optical properties of CsCaI3. From our calculations, we predict that CsCaI3 can form stable…
Nickel ditelluride (NiTe2), a new discovered type-II Dirac semimetal whose Dirac node lies close to its Fermi level, is expected to exhibit exotic phenomena including Lifshitz transition and superconductivity. As we know, defects are…
B diffusion measurements are used to probe the basic nature of self-interstitial 'point' defects in Ge. We find two distinct self-interstitial forms - a simple one with low entropy and a complex one with entropy ~30 k at the migration…
We report x-ray diffraction, electrical resistivity, and magnetoresistance measurements on Bi2Se3 under high pressure and low temperature conditions. Pressure induces profound changes in both the room temperature value of the electrical…
Bi2Te3/Fe1+yTe heterostructures are known to exhibit interfacial superconductivity between two non-superconducting materials: Fe1+yTe as the parent compound of Fe-based superconducting materials and the topological insulator Bi2Te3. Here,…
In this work, we studied the bulk band structure of a topological insulator (TI) Bi2Se3 and determined the contributions of the Bi and Se orbital states to the valence bands using standing wave-excited hard x-ray photoemission spectroscopy…
SnSe monolayer with orthorhombic Pnma GeS structure is an important two-dimensional (2D) indirect band gap material at room temperature. Based on first-principles density functional theory calculations, we present systematic studies on the…
We study adsorption sites of a single Xe adatom on Nb(110) surface using a density functional theory approach: The on-top site is the most favorable position for the adsorption. We compare the binding features of the present study to…
The binary Bi-chalchogenides, Bi2Ch3, are widely regarded as model examples of a recently discovered new form of quantum matter, the three-dimensional topological insulator (TI) [1-4]. These compounds host a single spin-helical surface…
The family of multi-layered superconductors derived from the doped topological insulator Bi$_2$Se$_3$ has been found to be unusually robust against non-magnetic disorder. Recent experimental studies have highlighted the fact that the…
We report first-principles microscopic calculations of the formation energy, electrical activity, and magnetic moment of Co dopants and a variety of native defects in TiO2 anatase. Using these results, we use equilibrium thermodynamics to…
The electronic structures of boron nitride nanotubes (BNNTs) doped by organic molecules are investigated with density functional theory. Electrophilic molecule introduces acceptor states in the wide gap of BNNT close to the valence band…
Hexagonally deformed Fermi surfaces and strong nesting, found in topological insulators (TIs) such as $Bi_2Se_3$ and $Bi_2Te_3$, have led to several predictions of the existence of Density Wave order in these systems. Recent evidence for…
We have observed a large as well as path-dependent spontaneous exchange bias (H$_{SEB}$) ($\sim$30-60 mT) in a nanocomposite of BiFeO$_3$-Bi$_2$Fe$_4$O$_9$ across 5-300 K when it is measured in an unmagnetized state following zero-field…
Bi2Se3 and Bi2Te3 are layered compounds of technological importance, being excellent thermoelectric materials as well as topological insulators. We report density functional theory calculations of the atomic, electronic and thermoelectric…
We study unconventional superconductivity in thin exfoliated single crystals of a promising 3D topological superconductor candidate, Nb-doped Bi$_2$Se$_3$ through Andreev reflection spectroscopy and magneto-transport. Measurements of…
Although $\beta$-TeO$_2$ is a promising $p$-type transparent conducting oxide (TCO) due to the large optical gap ($\sim$ 3.7 eV) and a light effective hole mass, its hole dopability still remains unexplored. In this work, electronic…
The electronic and magnetic properties of iron-doped topological insulator Bi1.84-xFe0.16CaxSe3 single crystals were studied. By co-doping Fe and Ca atoms, ferromagnetic bulk states with different carrier density (from n-type to p-type)…
A microscopic mechanism is proposed for a dramatic sign change of the Seebeck coefficient from positive to negative sign by the introduction of antisite defects in Fe$_2$VAl based on bipolar random Anderson model (BPRAM), which incorporates…
The chalcogenide Bi$_2$Se$_3$ can attain the three dimensional (3D) Dirac semimetal state under the influence of strain and microstrain. Here we report the presnece of large linear magnetoresistance in such a Bi$_2$Se$_3$ crystal. The…