Related papers: Helicity sensitive terahertz radiation detection b…
Subwavelength-thin metasurfaces have shown great promises for the control of optical wavefronts, thus opening new pathways for the development of efficient flat optics. In particular, Huygens' metasurfaces based on all-dielectric resonant…
We developed a theory of collective plasma oscillations in a dc current-biased field effect transistor with interdigitated dual grating gate and demonstrated a new mechanism of electron plasma instability in this structure. The instability…
In complex oxides, the electrons under the influence of competing energetics are the cornerstone of coexistence (or phase-separation) of two or more electronic/magnetic phases in same structural configuration. Probing of growth and…
High-harmonic generation (HHG), a typical nonlinear optical effect, has been actively studied in electron systems such as semiconductors and superconductors. As a natural extension, we theoretically study HHG from electric polarization,…
Nonlinear helicity-dependent photocurrents have been reported in 3D topological materials lacking inversion symmetry. Here, we theoretically study the charge and spin photocurrents generated by linear and circularly polarized radiation in…
The intrinsic performance of "type-II" InP/GaAsSb double heterojunction bipolar transistors (DHBTs) towards and beyond THz is predicted and analyzed based on a multi-scale technology computer aided design (TCAD) modeling platform calibrated…
We present a versatile confocal microscopy setup for optical second harmonic generation (SHG) and multi-photon spectroscopy that enables polarization-resolved studies of semiconductor bulk crystals and low-dimensional structures. The system…
Recent advances in time-domain terahertz (THz) spectroscopy have unveiled that resonantly-enhanced strong THz third-harmonic generation (THG) mediated by the collective Higgs amplitude mode occurs in s-wave superconductors, where…
The ultrashort laser excitation of Co/Pt magnetic heterostructures can effectively generate spin and charge currents at the interfaces between magnetic and nonmagnetic layers. The direction of these photocurrents can be controlled by the…
Chirality, a fundamental property of asymmetric structures, plays a crucial role in pharmaceutical, biological and chemical systems, offering a powerful tool for screening organic compounds. While the conventional optical chirality…
We are demonstrating the optical control of a specific state of the germanium telluride (GeTe) phase change material and its integration as control element for realizing extremely efficient optically reconfigurable THz devices. The…
The majority of sources of coherent optical radiation rely on laser oscillators driven by population inversion. Despite their technological importance in communications, medicine, industry, and other fields, it remains a challenge to access…
Van der Waals (vdW) structures of two-dimensional materials host a broad range of physical phenomena. New opportunities arise if different functional layers may be remotely modulated or coupled in a device structure. Here we demonstrate the…
We investigate the response of the micromechanical field-effect transistors (MMFETs) to the impinging terahertz (THz) signals. The MMFET uses the microcantilevers MC as a mechanically floating gate and the movable mirror of the Michelson…
The paper overviews experimental and theoretical studies of photogalvanic effects induced in BiSbTe- based three dimensional topological insulators by polarized terahertz radiation. We present the state-of-the-art of this subject, including…
Topological systems are inherently robust to disorder and continuous perturbations, resulting in dissipation-free edge transport of electrons in quantum solids, or reflectionless guiding of photons and phonons in classical wave systems…
Polarization dependent photocurrent spectra are measured on a (001) $\beta$-Ga$_{2}$O$_{3}$ Schottky photodetector, where the linear polarization of light is rotated within the ab plane. Three spectral peaks at 4.92 eV, 5.15 eV, and 5.44 eV…
Dielectric resonant metasurfaces can be utilized for efficient high harmonic generation, which has been explored here in this effort for a high-efficient Germanium metasurface for upconverted full-Stokes imaging at 1.33-micron wavelength by…
We report on spin ratchet currents driven by terahertz radiation electric fields in a Co/Pt magnetic metamaterial formed by triangle-shaped holes forming an antidots lattice and subjected to an external magnetic field applied…
We present a novel approach to enhance THz nonlinearity by the resonant excitation of two-dimensional plasmons in grating-gate plasmonic crystals. Using a high-electric-field THz pump-THz probe technique, we investigate the nonlinear…