Related papers: Electric-field switchable second-harmonic generati…
In 1H monolayer transition metal dichalcogenide, the inversion symmetry is broken, while the reflection symmetry is maintained. On the contrary, in the bilayer, the inversion symmetry is restored, but the reflection symmetry is broken. As a…
In this letter we show by means of first principle numerical simulations that electron-hole interaction significantly contributes to the second-harmonic generation spectrum of h-BN or MoS$_2$ monolayers. Specifically, it doubles the signal…
Coulomb bound electron-hole pairs, excitons, govern the optical properties of semi-conducting transition metal dichalcogenides like MoS$_2$ and WSe$_2$. We study optical transitions at the K-point for 2H homobilayer MoS$_2$ in Density…
Chip-scale nonlinear optics enables strong light-matter interactions within compact devices, serving as a fundamental platform for multifunctional integrated photonics from classical optical signal processing to quantum information…
Over the past years, transition metal dichalcogenides (TMDs) have attracted attention as potential building blocks for various electronic applications due to their atomically thin nature. An exciting development is the recent success in…
Understanding the nature of sliding ferroelectricity is of fundamental importance for the discovery and application of two-dimensional ferroelectric materials. In this work, we investigate the phenomenon of switchable polarization in a…
In moir\'e crystals resulting from the stacking of twisted two-dimensional (2D) layered materials, a subtle adjustment in the twist angle surprisingly gives rise to a wide range of correlated optical and electrical properties. Herein, we…
We report that an external electric field applied normal to bilayers of transition-metal dichalcogenides TX2, M = Mo, W, X = S, Se, creates significant spin-orbit splittings and reduces the electronic band gap linearly with the field…
Moir\'e heterobilayers exhibiting spatially varying band alignment and electron and hole localization that can be precisely controlled through the twist angle have emerged as exciting platforms for studying complex quantum phenomena. While…
We report the experimental observation of quadrupolar exciton states in the reflectance contrast spectrum of 2$H$-stacked bilayer MoSe$_2$. The application of a vertical electric field results in a quadratic energy redshift of these…
The theory of inter-spin-subband electric dipole spin resonance in transition metal dichalcogenide heterobilayers is proposed. Our symmetry analysis demonstrates that, in contrast to monolayers, the reduced symmetry of heterobilayers…
We demonstrate a new, nonlinear optical effect of electric currents. First, a steady current is generated by applying a voltage on a doped GaAs crystal. We demonstrate that this current induces second-harmonic generation of a probe laser…
Nonlinear frequency conversion provides essential tools for light generation, photon entanglement, and manipulation. Transition metal dichalcogenides (TMDs) possess huge nonlinear susceptibilities and 3R-stacked TMD crystals further combine…
Piezoelectricity appears in the inversion asymmetric crystal that converts mechanical deformational force to electricity. Two-dimensional transition metal dichalcolgenide (TMDC) monolayers exhibit the piezoelectric effect due to the…
While all media can exhibit first-order conductivity describing current linearly proportional to electric field, $E$, the second-order conductivity, $\sigma^{(2)}$ , relating current to $E^2$, is nonzero only when inversion symmetry is…
We show that spatially structured radiation generates second harmonic in a two-dimensional system even if the system is homogeneous and isotropic. The effect originates from non-locality of electric response to structured electromagnetic…
We theoretically investigate second harmonic generation that originates from the nonlinear, magnetic Lorentz force term from single and multiple apertures carved on thick, opaque metal substrates. The linear transmission properties of…
A comprehensive study of second harmonic generation on thermally oxidized MoS2 flakes with thickness ranging from monolayer up to seven layers is presented. Observing the fundamental nonlinear behavior for non-treated and oxidized MoS2…
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…
In the second-order response regime, the Hall voltage can be nonzero without breaking the time-reversal symmetry, as long as the system is noncentrosymmetric. There are multiple mechanisms with different scaling rules that contribute to the…