相关论文: Nonlinear spectroscopy of collective modes in exci…
Rydberg excitons (analogues of Rydberg atoms in condensed matter systems) are highly excited bound electron-hole states with large Bohr radii. The interaction between them as well as exciton coupling to light may lead to strong optical…
We theoretically investigate the emergence of quantum nonlinearities in the optical response of lattices of two-level quantum emitters coherently driven by a laser. For subwavelength lattice periods, where the system behaves as a quantum…
The bound electron-hole pairs known as excitons govern the optical properties of insulating solids. While their behavior in equilibrium is well-understood theoretically, the nonequilibrium regime at high excitation densities-where phenomena…
Collective excitations presenting nonlinear dynamics are fundamental phenomena with broad applications. A prime example is nonlinear optics, where diverse frequency mixing processes are central to communication, sensing, wavelength…
Temperature influences the performance of two-dimensional materials in optoelectronic devices. Indeed, the optical characterization of these materials is usually realized at room temperature. Nevertheless most {\it ab-initio} studies are…
The optical properties of two-dimensional materials are exceptional in several respects. They are highly anisotropic and frequently dominated by excitonic effects. Dipole-allowed second order non-linear optical properties require broken…
The full time-dependent four-wave mixing polarization in quantum dots is microscopically calculated, taking into account acoustic phonon-assisted transitions between different exciton states of the dot. It is shown that quite different…
We identify signatures of the intrinsic nonlinear interaction between light and mechanical motion in cavity optomechanical systems. These signatures are observable even when the cavity linewidth exceeds the optomechanical coupling rate. A…
We theoretically study dynamical excitonic condensates occurring in bilayers with an imposed chemical potential difference and in photodoped semiconductors. We show that optical spectroscopy can experimentally identify phase-trapped and…
In-plane polarized light experiences a non-trivial topological evolution as it propagates resonantly in a M\"obius ring resonator. The resultant geometric phase varies continuously when changing the light ellipticity, which leads to…
The real part of optical conductivity $\text{Re}\sigma(\omega)$ of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. By using the time-dependent density-matrix…
In this Letter, we provide experimental evidence of nonlinear wave propagation in a triangular lattice of repulsive magnets supported by an elastic foundation of thin pillars and we interpret all the individual features of the nonlinear…
We address nonlinear signal switching between two low-index defect channels induced in periodic optical lattices. In contrast to conventional directional couplers, where the guiding mechanism is total internal reflection or refraction, in…
Excitons are vital in the photophysics of materials, especially in low-dimensional systems. The conceptual and quantitative understanding of excitonic effects in nonlinear optical (NLO) processes is more challenging compared to linear ones.…
The interaction of a single-cycle THz electric field with the topological insulator $\mathrm{MnBi}_2\mathrm{Te}_4$ triggers strongly anharmonic lattice dynamics, promoting fully coherent energy transfer between the otherwise non-interacting…
Excitons play a key role in the linear optical response of 2D materials. However, their significance in the highly nonlinear optical response to intense mid-infrared light has often been overlooked. Using hBN as a prototypical example, we…
We theoretically investigate coherent optical excitations of collective modes in two-band BCS superconductors, which accommodate two Higgs modes and one Leggett mode corresponding, respectively, to the amplitude and relative-phase…
When a continuous symmetry of a physical system is spontaneously broken, two types of collective modes typically emerge: the amplitude and phase modes of the order-parameter fluctuation. For superconductors, the amplitude mode is recently…
Time-resolved photoluminescence spectra after nonresonant excitation show a distinct 1s resonance, independent of the existence of bound excitons. A microscopic analysis identifies excitonic and electron-hole plasma contributions. For low…
In the framework of linear optics, light fields do not interact with each other in a medium. Yet, when their field amplitude becomes comparable to the electron binding energies of matter, the nonlinear motion of these electrons emits new…