Related papers: Nonlinear optical response and spontaneous polariz…
Polarized and azimuthal dependencies of optical second harmonics generation (SHG) at the surface of noncentrosymmetric semiconductor crystals have been measured on polished surfaces of ZnSe(100), using a fundamental wavelength of 1.06$\mu…
Atomically thin crystals have recently been the focus of attention in particular after the synthesis of graphene, a monolayer hexagonal crystal structure of carbon. In this novel material class the chemically derived graphenes have…
MnBi2Te4 is a van der Waals topological insulator with intrinsic intralayer ferromagnetic exchange and A-type antiferromagnetic interlayer coupling. Theoretically, it belongs to a class of structurally centrosymmetric crystals whose layered…
We propose a method for efficiently harnessing the quadratic optical response of two-dimensional graphene-like materials by theoretically investigating second harmonic generation from a current biased sheet placed within a planar active…
Because of the dominant role of the surface of molecules and their individuality, molecules behave dis-tinctively in a confined space, which has far-reaching implications in many physical, chemical and bio-logical systems. Here, we…
For centrosymmetric materials such as monolayer graphene, no optical second harmonic generation (SHG) is generally expected because it is forbidden under the electric-dipole approximation. Yet we observed a strong, doping induced SHG from…
The random laser action with coherent feedback by second-harmonic generation (SHG) was experimentally demonstrated in this paper. Compared with the conventional random laser action based on photoluminescence effect, which needs strong…
Research on graphene and other two-dimensional (2D) materials, such as silicene, germanene, phosphorene, hexagonal boron nitride (h-BN), graphitic carbon nitride (g-C3N4), graphitic zinc oxide (g-ZnO) and molybdenum disulphide (MoS2), has…
We present an analytical theory of second harmonic generation (SHG) in hybrid structures combining a nonlinear 2D crystal with a dielectric metasurface waveguide. The theory describes the excitation spectrum and enhancement of SHG at both…
While two-dimensional (2D) materials have intriguing second-order nonlinearities with ultrahigh coefficient and electrical tunability, their atomic layer thicknesses hinder explorations of other optical frequency-conversions (OFCs) than…
First-principles calculation has been performed to investigate the stability and electronic properties of double-layer graphene heterostructure (DLGH). In this system, two graphene layers are separated by hexagonal boron-nitride (h-BN)…
The available synthesized silicene-like structures have been only realized on metallic substrates which are very different from the standalone buckled silicene, e.g. the Dirac cone of silicene is destroyed due to lattice distortion and the…
Recent discovery of a novel hexagonal phase of GeSe (Gamma-GeSe) has triggered great interests in nanoelectronics applications owing to its electrical conductivity of bulk phase even higher than graphite while its monolayer is a…
The electronic structure of few-layer graphene (FLG) samples with crystalline order was investigated experimentally by infrared absorption spectroscopy for photon energies ranging from 0.2 - 1 eV. Distinct optical conductivity spectra were…
Two dimensional (2D) topological insulators (TIs) and topological superconductors (TSCs) have been intensively studied for recent years due to its great potential for dissipationless electron transportation and fault-tolerant quantum…
Second harmonic generation is a powerful tool directly connected to the symmetry of materials. Phase transitions, lattice rotations or electromagnetic coupling in multiferroic compounds can be revealed by using second harmonic…
Graphene is a 2-dimensional (2D) carbon allotrope with the atoms arranged in a honeycomb lattice. The low-energy electronic excitations in this 2D crystal are described by massless Dirac fermions that have a linear dispersion relation…
Graphene possesses remarkable electronic, optical and mechanical properties that have taken the research of two-dimensional relativistic condensed matter systems to prolific levels. However, the understanding of how its nonlinear optical…
In modern two-dimensional (2D) materials, such as graphene-based systems and atomically-thin transition-metal dichalcogenides, the interplay of strong electronic correlations, tunable moir\'e superlattices, and nontrivial band topology has…
The vertical integration of multiple two-dimensional (2D) materials in heterostructures, held together by van der Waals forces, has opened unprecedented possibilities for modifying the (opto-)electronic properties of nanodevices. Graphene,…