相关论文: Terahertz-induced second-harmonic generation in qu…
Motivated by recent experiments on pump-induced polar ordering in the quantum paraelectric SrTiO$_3$, we study a driven phonon system close to a second order phase transition. Analyzing its classical dynamics, we find that sufficiently…
Ultrasonic velocity measurements on the magnetoelectric multiferroic compound CuFeO2 reveal that the antiferromagnetic transition observed at TN1 = 14 K might be induced by an R-3m -> C2/m pseudoproper ferroelastic transition (G. Quirion,…
The heat transport in heavy-doped n-GaAs has been investigated at temperatures T=300 K and 77 K using the irradiation of the metal-semiconductor contact by modulated CO_{2}-laser radiation. It is shown this approach giving an opportunity to…
We present theoretical studies of high-order harmonic generation (HHG) driven by plasmonic fields in two-electron atomic systems. Comparing the two-active electron and single-active electron approximation models of the negative hydrogen ion…
We solve for the finite temperature collective mode dynamics in the Holstein-double exchange problem, using coupled Langevin equations for the phonon and spin variables. We present results in a strongly anharmonic regime, close to a…
Harmonic generation provides an efficient tool for the study of ultrafast nonlinear dynamics. We report on time-resolved optical-pump terahertz-harmonic-generation spectroscopic investigation of ultrafast nonlinearity in a prototypical…
The soft modes in the two- and eight-direction order-disorder ferroelectrics are calculated under the mean-field approximation. We find that the conventional method of the pseudospin model to calculate the soft-mode frequency is incorrect,…
Infrared reflectivity and time-domain terahertz transmission spectra of EuTiO3 ceramics revealed a polar optic phonon at 6 - 300K, whose softening is fully responsible for the recently observed quantum paraelectric behaviour. Even if our…
Investigating the non-linear transport regime in a quantum dot heat engine described by the Anderson-Holstein model, it is shown that a finite electron-phonon interaction leads to a charge induced phonon generation that stimulates a phonon…
The response to external terahertz (THz) irradiation from the silicon carbide nanostructures prepared by the method of substitution of atoms on silicon is investigated. The kinetic dependence of the longitudinal voltage is recorded at room…
The coherent nonlinear dynamics between collective excitations, such as magnons and phonons, drive emergent phenomena in quantum materials, yet their direct observation remains a central challenge. Here, using double-terahertz-pump…
Optical second-harmonic generation (SHG) is a nonlinear parametric process that doubles the frequency of incoming light. Only allowed in non-centrosymmetric materials, it has been widely used in frequency modulation of lasers, surface…
Ferroelectric materials offer unprecedented ultrafast responses and are of great interest for the development of new polarizable media under the influence of an electromagnetic field. Recent research efforts have demonstrated the role of…
We show that electron drag by nonequilibrium phonons describes the actual waveform and spectrum of terahertz pulses generated during femtosecond laser irradiation of metals. In contrast to previous models, there is a picosecond delay in the…
Symmetry governs the selection rules of light-matter interactions in crystalline materials, making symmetry manipulation a powerful tool for tuning their optical properties. Here, we demonstrate that the hot-electron injection from a…
Phonon densities of states (DOS) of bcc $\alpha$-$^{57}$Fe were measured from room temperature through the 1044K Curie transition and the 1185K fcc $\gamma$-Fe phase transition using nuclear resonant inelastic x-ray scattering. At higher…
Identification of pairing mechanisms leading to the unconventional superconductivity realized in copper-oxide, heavy-fermions, and organic compounds is one of the most challenging issues in condensed-matter physics. Clear evidence for an…
Highly-tunable coherent light generation is crucial for many important photonic applications. Second-harmonic generation (SHG) is a dominant approach for this purpose, which, however, exhibits a trade-off between the conversion efficiency…
Using thermal effective field theory, we present a self-consistent perturbative formulation of the Higgs phase sphaleron rate after a radiatively-induced first-order phase transition. This gauge-invariant formulation is based on…
2H-NbSe2 is an archetypal system in which superconductivity and charge-density-wave (CDW) coexist and compete macroscopically with each other. In particular, this interplay also manifests in their dynamical fluctuations. As a result, the…