Related papers: Domain-Direct Band Gaps: Classification and Materi…
Dispersionless electronic bands lead to an extremely high density of states and suppressed kinetic energy, thereby increasing electronic correlations and instabilities that can shape emergent ordered states, such as excitonic,…
Built on a realistic multiband tight-binding model, mirror symmetry is used to map a calcium-intercalated bilayer graphene Hamiltonian into two independent single layer graphene-like Hamiltonians with renormalized hopping. The…
The optical conductivity of MgB$_2$ has been determined on a dense polycrystalline sample in the spectral range 6 meV - 4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. $\sigma_{1}(\omega)$…
New developments in the field of topological matter are often driven by materials discovery, including novel topological insulators, Dirac semimetals and Weyl semimetals. In the last few years, large efforts have been performed to classify…
In this paper, the 2D band structure of a mixed-mode metamaterial resonator array for in-plane waves is investigated. The band structure in the interior and on the boundary of the irreducible Brillouin zone as well as 1D dispersion diagrams…
We classify all possible gap-closing procedures which can be achieved in two-dimensional time-reversal invariant noncentrosymmetric systems. For exhaustive classification, we examine the space group symmetries of all 49 layer groups lacking…
Flat bands have attracted considerable interest in condensed matter physics because they provide a fertile platform for realizing strongly correlated and topological quantum phases. To date, however, most studies have focused on flat bands…
Due to the lack of two-dimensional silicon-based semiconductors and the fact that most of the components and devices are generated on single-crystal silicon or silicon-based substrates in modern industry, designing two-dimensional…
Monolayers of transition metal dichalcogenides (TMDCs) exhibit an exceptionally strong Coulomb interaction between charge carriers due to the two-dimensional carrier confinement in connection with weak dielectric screening. High densities…
In$_2$Se$_3$ is a semiconductor material that can be stabilized in different crystal structures (at least one 3D and several 2D layered structures have been reported) with diverse electrical and optical properties. This feature has plagued…
For a wide class of technologically relevant compound III-V and II-VI semiconductor materials AC and BC mixed crystals (alloys) of the type A(x)B(1-x)C can be realized. As the electronic properties like the bulk band gap vary continuously…
In our present work, five previously proposed sp$^3$ carbon crystals were suggested as silicon allotropes and their stabilities, electronic and optical properties were investigated by first-principles method. We find that these allotropes…
We investigate theoretically the properties of s-wave multiband superconductors in the weak coupling (BCS) limit in the presence of pair-breaking effects of magnetic field. It is shown that a qualitatively new gapless superconducting state…
Using density functional theory, the structural and electronic-structure properties of a recently discovered, zero-dimensional antimony halide perovskite are studied. It is found that the herein considered material EtPySbBr$_\mathrm{6}$…
We develop a mathematical and numerical framework for studying evanescent waves in subwavelength band gap materials. By establishing a link between the complex Brillouin zone and various Hermitian and non-Hermitian phenomena, including…
We demonstrate that the electronic bandstructure extracted from quasi-particle interference spectroscopy [Nat. Phys. 9, 468 (2013)] and the theoretically computed form of the superconducting gaps [Proc. Nat. Acad. Sci. 111, 11663 (2014)]…
Phononic crystals (PCs) and metamaterials are artificially structured materials with the unprecedented property of the existence of complete stop-bands. However, the generally narrow width of the stop-bands in such materials severely limits…
Two possible phases of superhard material BC3 originating from the cubic diamond structure are investigated by ab initio pseudopotential density functional method using generalized gradient approximation (GGA). We calculate their elastic…
The electronic band gap in conventional semiconductor materials, such as silicon, is fixed by the material's crystal structure and chemical composition. The gap defines the material's transport and optical properties and is of great…
Dispersionless flat bands are proposed to be a fundamental ingredient to achieve the various sought after quantum states of matter including high-temperature superconductivity1-4 and fractional quantum Hall effect5-6. Materials with such…