Related papers: Narrowing band gap chemically and physically: Cond…
Applying pressure around megabar is indispensable in the synthesis of high-temperature superconducting hydrides, such as SH$_3$ and LaH$_{10}$. Stabilizing the high-pressure phase of hydride around ambient condition is a severe challenge.…
Two-dimensional polyaniline sheet has been recently synthesized and found that it is a semiconductor with indirect band gap. Polyaniline nanoribbons decomposed from two-dimensional polyaniline sheet (C3N sheet) are investigated using…
Density functional methods have been used to calculate the electronic properties of aligned smalldiameter single-walled carbon nanotubes under hydrostatic pressures. Abrupt pressure induced semiconductor-metal and metal-semiconductor…
Search for one dimensional (1D) van der Waals materials has become an urgent need to meet the demand as building blocks for high performance, miniaturized, lightweight device applications. Polyyne, a 1D atomic chain of carbon is the…
We study the modifications on the ground and excited state properties of polycyclic aromatic hydrocarbons (PAHs), induced by the variation of concavity and $\pi$-connectivity. Inspired by experimentally feasible systems, we study three…
Bilayer graphene is a highly promising material for electronic and optoelectronic applications since it is supporting massive Dirac fermions with a tuneable band gap. However, no consistent picture of the gap's effect on the optical and…
Functionalized polcyclic aromatic hydrocarbons (PAHs) are an interesting class of molecules in which the electronic state of the graphene-like hydrocarbon part is tuned by the functional group. Searching for new types of donor and acceptor…
We performed high-throughput density functional theory calculations of optical matrix elements between band edges across a diverse set of non-magnetic two-dimensional monolayers with direct band gaps. Materials were ranked as potential…
The recent discovery of methods to isolate graphene, a one-atom-thick layer of crystalline carbon, has raised the possibility of a new class of nano-electronics devices based on the extraordinary electrical transport and unusual physical…
The transition from insulator to conductor can be achieved in some materials but requires modification of both the arrangement of atoms and their electronic configurations. This is often achieved by doping. Here we reveal a mechanism the…
A comprehensive understanding of the physical origin of the unique magnetic and transport properties of A_(1-x)A'^xMnO_3 manganites (A = trivalent rare-earth and A' = divalent alkali-earth metal) is still far from being achieved. The…
The application of pressure to elemental bismuth reduces its conduction-valence band overlap, and results in a semimetal-semiconductor (SMSC) transition around 25 kbar. This transition is nominally of the topological "Lifshitz" Fermi…
We predict the new type of phase transition in quasi one-dimensional system of interacting electrons at high magnetic fields, the stabilization of a density wave which transforms a two dimensional open Fermi surface into a periodic chain of…
Dynamic control of conductivity and optical properties via atomic structure changes is of tremendous technological importance in information storage. Energy consumption considerations provide a driving force toward employing thin materials…
The transition between gapped (semiconducting) and gapless (metallic) phases and tunability of bandgap in materials is a very lucrative yet considerably challenging goal for new-age device preparation. For bulk materials and for…
Using Quantum Monte Carlo (QMC) calculations, we investigate the insulator-metal transition observed in liquid hydrogen at high pressure. Below the critical temperature of the transition from the molecular to the atomic liquid, the…
Using first-principles calculations we show that the band gap of bilayer sheets of semiconducting transition metal dichalcogenides (TMDs) can be reduced smoothly by applying vertical compressive pressure. These materials undergo a universal…
We have studied dense hydrogen and deuterium experimentally up to 320 GPa and using ab initio molecular dynamic (MD) simulations up to 370 GPa between 250 and 300 K. Raman and optical absorption spectra show significant anharmonic and…
We report on the first experimental observation of an apparent metal insulator transition in a 2D electron gas confined in an InAs quantum well. At high densities we find that the carrier mobility is limited by background charged impurities…
Many properties of layered materials change as they are thinned from their bulk forms down to single layers, with examples including indirect-to-direct band gap transition in 2H semiconducting transition metal dichalcogenides as well as…