Related papers: Nonlinear frequency-asymmetric optical response in…
We establish a steady-state theory for nonlinear optical conductivity in pseudo-Hermitian systems. We derive compact formulas for the first and second order conductivity tensors in both the velocity and length gauges and prove their exact…
We present a unifying framework that allows us to study the mixed crystalline-electromagnetic responses of topological semimetals in spatial dimensions up to $D = 3$ through dimensional augmentation and reduction procedures. We show how…
Nonlinear electrical response permits a unique window into effects of band structure geometry. It can be calculated either starting from a Boltzmann approach for small frequencies, or using Kubo's formula for resonances at finite frequency.…
Weyl semimetals are a three-dimensional topological phase of matter with isolated band touchings in the Brillouin Zone. These points have an associated chirality, and many of the proposals to detect the Weyl semimetal state rely on the…
Linear response theory plays a prominent role in various fields of physics and provides us with extensive information about the thermodynamics and dynamics of quantum and classical systems. Here we develop a general theory for the linear…
Chirality is an intriguing property of certain molecules, materials or artificial nanostructures, which allows them to interact with the spin angular momentum of the impinging light field. Due to their chiral geometry, they can distinguish…
Coherent nonlinear optical micro-spectroscopy is a frequently used tool in modern material science, as it is sensitive to many different local observables, which comprise, among others, crystal symmetry and vibrational properties. The…
The optical conductivity is the basic defining property of materials characterizing the current response toward time-dependent electric fields. In this work, following the approach of Kubo's response theory, we study the general properties…
The nonlinear response to an oscillating field is calculated for a kinetic trap model with an exponential density of states and the results are compared to those for the model with a Gaussian density of states. The calculations are limited…
The dynamical encirclement around a second order exceptional point (EP) and corresponding chirality driven nonadiabatic modal dynamics have attracted enormous attention in the topological study of various non-Hermitian systems. However,…
Chiral photonics aims to control and engineer light handedness for many applications in optical communications, biological and chemical sensing, and quantum technologies. While traditional approaches focus on engineering strong linear…
Nonlinear electrical conduction primarily mediated by an orbital texture is observed in chiral semiconductor Te. We determine the enantiospecific sign of the nonlinear conductance and identify anomalies in its carrier-density dependence.…
Chiral photonics provides powerful routes for controlling the light handedness, yet nonlinear chiral responses are typically associated with intricate three-dimensional systems. Here, we demonstrate that strong nonlinear chirality can…
The nonlinear optical responses of chiral phonons to terahertz and infrared light are studied using the nonlinear response theory. We show that the photo-induced angular momentum increases with the square of the chiral-phonon relaxation…
We consider classical response in a strongly chaotic (mixing) system. As opposed to the case of stable dynamics, the nonlinear classical response in a chaotic system vanishes at large times. The physical behavior of the nonlinear response…
The recent surge of interest in temporal modulation schemes to induce magnet-free non-reciprocity has inspired several exciting opportunities for photonic technology. Here, we investigate a scheme to realize free-space isolators and highly…
We present a one dimensional model for the nonlinear response of a colloidal crystal to intense light illumination along a high symmetry direction. The strong coupling between light and the colloidal lattice, via the electric gradient force…
Topological insulators (TI) are highly attractive platforms for next-generation optoelectronic and photonic devices. Spin-momentum locking of topological surface states enhance their nonlinear optical responses and sensitivities, especially…
A dielectric material's response to light is macroscopically described by electric displacement fields due to polarization and susceptibility, but the atomistic origin is light-cycle-driven motion of electron densities in the restoring…
A magnetic toroidal moment is a fundamental electronic degree of freedom in the absence of both spatial inversion and time-reversal symmetries and gives rise to novel multiferroic and transport properties. We elucidate essential model…