Related papers: Terahertz Bloch oscillator with a modulated bias
We develop a comprehensive, elegant theory to explain terahertz (THz) emission from a superlattice over a wide range of applied electric field,which shows excellent agreement between theory andexperiment for a GaAs/Al{0.3}Ga{0.7As…
Terahertz (THz) radiation, spanning from 0.3 to 3x10^12 Hz, fills the crucial gap between the microwave and infrared spectral range. THz technology has found applications in various fields, from imaging and sensing to telecommunication and…
Terahertz quantum cascade lasers (THz QCLs) are chip-scale semiconductor lasers operating in the frequency range between 1-6 THz, useful as compact sources for spectroscopy, communications, and non-destructive imaging and testing. Here, we…
We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch…
We have studied Bloch electrons in a perfect unidirectional superlattice subject to crossed electric and magnetic fields, where the magnetic field is oriented ``in-plane'', i.e. in parallel to the sample plane. Two orientation of the…
Using adiabatic expansions formalism, upper bounds for interband transitions for Bloch electrons in slowly varying in time electric fields are obtained. These bounds imply the validity of one-band approximation on long time scales.
The static and high-frequency differential conductivity of a one-dimensional superlattice with parabolic miniband, in which the dispersion law is assumed to be parabolic up to the Brillouin zone edge, are investigated theoretically. Unlike…
A novel DC and AC driving configuration is proposed for semiconductor superlattices, in which the THz AC driving is provided by an intense bichromatic cw laser. The two components of the laser, usually in the visible light range, are near…
We investigate theoretically the feasibility of generation and amplification of terahertz radiation in aligned achiral carbon nanotubes (zigzag and armchair) in comparison with a superlattice in the presence of a constant (dc) and…
We examine phenomenon of electromagnetic transparency in semiconductor superlattices (having various miniband dispersion laws) in the presence of multi-frequency periodic and non-periodic electric fields. Effects of induced transparency and…
A connection of a variety of tight-binding models of noninteracting electrons on a rectangular lattice in a magnetic field with theta functions is established. A new spectrum generating symmetry is discovered which essentialy reduces the…
A source which generates sustained terahertz electromagnetic radiation (oscillator) controllable by an applied voltage is proposed. The structure consists of a nanocomposite slab containing metal nanorods enclosed between two graphene…
Artificial crystals such as moir\'e superlattices can have a real-space periodicity much larger than the underlying atomic scale. This facilitates the presence of Bloch oscillations in the presence of a static electric field. We demonstrate…
We show that a moving Josephson vortex in spatially modulated layered superconductors generates out-of-plane THz radiation. Remarkably, the magnetic and in-plane electric fields radiated are of the same order, which is very unusual for any…
A transmon qubit embedded in a high-impedance environment acts in a way dual to a conventional Josephson junction. In analogy to the AC Josephson effect, biasing of the transmon by a direct current leads to the oscillations of voltage…
We show that superlattices based on zero-gap semiconductors such as graphene and mercury telluride exhibit characteristic Bloch--Zener oscillations that emerge from the coherent superposition of Bloch oscillations and multiple Zener…
The coherent radiation spectrum of two-level polar molecules with UV transition is studied at the multiphoton resonant excitation by a moderately strong laser field. The spectrum corresponding to harmonic generation and low-frequency…
Terahertz (THz) sciences and technologies have contributed to a rapid development of a wide range of applications and expanded the frontiers in fundamental science. Spintronic terahertz emitters offer conceptual advantages since the spin…
We present theoretical and numerical results on the dynamics of ultracold atoms in an accelerated single- and double-periodic optical lattice. In the single-periodic potential Bloch oscillations can be used to generate fast directed…
Terahertz (THz) radiation by beating of two laser beams in a groove density and magnetized hot plasma is discussed theoretically. In this mechanism, the ponderomotive force leads to a nonlinear oscillatory current that resonantly excites…