We report the first-principles electronic structure of BiVO4, a promising photocatalyst for hydrogen generation. BiVO4 is found to be a direct band gap semiconductor, despite having band extrema away from the Brillouin zone center. Coupling between Bi 6s and O 2p forces an upward dispersion of the valence band at the zone boundary; however, a direct gap is maintained via coupling between V 3d, ...

We report measurements of the momentum dependence of the superconducting gap in Bi2Sr2CaCu2O81x with angle-resolved photoemission spectroscopy using a dense sampling of the Brillouin zone in the vicinity of the Fermi surface. In the Y quadrant of the zone, where there are no complications from ghost bands caused by the superlattice, we find a gap function consistent within error bars to the for...

High-resolution angle-resolved photoelectron spectroscopy is used to examine the electronic band structure of FeTe_{0.5}Se_{0.5} near the Brillouin zone center. A consistent separation of the α_{1} and α_{2} bands is observed with little k_{z} dependence of the α_{1} band. First-principles calculations for bulk and thin films demonstrate that the antiferromagnetic coupling between the Fe atoms ...

Coherent acoustic phonons are generated in GaAs/AlAs superlattices by excitation with femtosecond laser pulses. Several modes of the acoustic phonon spectrum are observed, in agreement with the effect of zone folding in the mini-Brillouin zone of the superlattice. By applying successive pump pulses we are able to silence the first back-folded mode near q50, while selectively enhancing the coher...

D. L. Feng,* C. Kim, H. Eisaki, D. H. Lu, A. Damascelli, K. M. Shen, F. Ronning, N. P. Armitage, N. Kaneko, M. Greven, J.-i. Shimoyama, K. Kishio, R. Yoshizaki, G. D. Gu, and Z.-X. Shen Department of Physics, Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305 Department of Physics, Fudan University, Shanghai 200433, People’s Republic o...

The effect of similar atom substitution on the glass forming ability (GFA) Al86Ni9(Y, Sm)5 (x = (0, 1, 1.5, 2, 3, 4, 5)) metallic glasses (MGs) was explored basis theory Fermi sphere-Brillouin zone interaction. Similar (Sm) mainly affects static structure between Al atoms and Y atoms, changing diameter pseudo-Brillouin (KP). Its level Brillouin size is characterized with spectroscopy experiment...

Graphyne and graphdiyne families of flat carbon (sp2/sp) networks with high degrees of π-conjunction are attracting much attention due to their promising electronic, optical, and mechanical properties. In the present investigation we have studied the structural, mechanical, electrical and optical properties of halogenated graphdiyne and graphyne. The optical spectra of pure and halog...