相关论文: Off-centered Pb interstitials in PbTe

The density and correlations of topological defects are investigated numerically in a model of a d=2 elastic medium subject to a periodic quenched random potential. The computed density of defects decreases approximately exponentially with…

We have observed phase defects in quasi-2D Bose-Einstein condensates close to the condensation temperature. Either a single or several equally spaced condensates are produced by selectively evaporating the sites of a 1D optical lattice.…

We identify different types of the photonic band gaps (PBGs) of two dimensional magnetic photonic crystals (MPCs) consisting of arrays of magnetic cylinders and study the different tunability (by an external static magnetic field) of these…

A simple model based on the concept of resonant tunnelling clusters of lattice defects is used to explain the low temperature anomalies of hcp 4He crystals (mass decoupling from a torsional oscillator, shear modulus anomaly, dissipation…

The presence of defects in the narrow-gap semiconductors GaSb and InSb affects their dopability and hence applicability for a range of optoelectronic applications. Here, we report hybrid density functional theory based calculations of the…

Control of order-disorder phase transitions is a fundamental materials science challenge, underpinning the development of energy storage technologies such as solid oxide fuel cells and batteries, ultra-high temperature ceramics, and durable…

Ferroelectric materials are characterized by degenerate ground states with multiple polarization directions. In a ferroelectric capacitor this should manifest as equally favourable up and down polarization states. However, this ideal…

The synthesis and physical properties of the new distorted-Hollandite PbIr4Se8 are reported. Powder X-ray diffraction and transmission electron microscopy show that the structure consists of edge- and corner-sharing IrSe6 octahedra, with…

Single layer Pb on top of (111) surfaces of group IV semiconductors hosts charge density wave and superconductivity depending on the coverage and on the substrate. These systems are normally considered to be experimental realizations of…

The excitation of pulsation modes in beta Cephei and Slowly Pulsating B stars is known to be very sensitive to opacity changes in the stellar interior where T~2 10^5 K. In this region differences in opacity up to ~50% can be induced by the…

Sufficient conditions are found on the ion velocity distribution $f_i$ and potential amplitude for stability of steady electron holes moving at slow speeds, coinciding with the bulk of $f_i$. Fully establishing stability requires…

BAs was predicted to have an unusually high thermal conductivity at room temperature of 2000$\,$Wm$^{-1}$$\,$K$^{-1}$, comparable to that of diamond. However, the experimentally measured thermal conductivity of BAs single crystals is an…

The effect of the dipole-dipole interaction on the far-off-resonance optical dipole trapping scheme is calculated by a mean-field approach. The trapping laser field polarizes the atoms and the accompanying dipole-dipole energy shift deepens…

By stacking PbTe layers there is a non-monotonic topological phase transition as a function of the number of monolayers. Based on first principles calculations we find that the proper stacked crystal symmetry determines the topological…

\textit{Ab initio} random structure searching based on density functional theory is used to determine the ground-state structures of ice at high pressures. Including estimates of lattice zero-point energies, ice is found to adopt three…

PtBi$_2$ is a polymorphic system with interesting electronic properties. Here we report optimized crystal growth and structural characterization of pyrite-type and trigonal modification of PtBi$_2$. Selected area electron diffraction, X-ray…

We present our angle resolved photoelectron spectroscopy (ARPES) and density functional theory results on quaternary topological insulator (TI) BiSbTe1.25Se1.75 (BSTS) confirming the non-trivial topology of the surface state bands (SSBs) in…

Lattice dynamics for five ordered PMN supercells were calculated from first principles by the frozen phonon method. Maximal symmetries of all supercells are reduced by structural instabilities. Lattice modes corresponding to these…

We present the charged-particle pseudorapidity density in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02\,\mathrm{Te\kern-.25exV}$ in centrality classes measured by ALICE. The measurement covers a wide pseudorapidity range from $-3.5$ to…

A limited number of 2D and 3D materials under a constant pressure contract in volume upon heating isobarically; this anomalous phenomenon is known as the negative thermal expansion (NTE). In this paper, the NTE anomaly is observed in 1D…