Related papers: Terahertz detection with delta-doped GaAs/AlAs mul…
We present a two-well terahertz (THz) quantum cascade laser designed for high temperature operation based on the InGaAs/AlInAs material system. The lighter effective mass and higher energy barriers increase the gain at high temperatures (T…
Blazars with redshifts z<0.1 are likely candidates for detection at energies in the range 300 GeV - 50 TeV with Cerenkov telescopes and scintillator arrays. We present gamma-ray flux predictions for a sample of 15 nearby flat-spectrum radio…
We report a fast, room temperature detection scheme for the polarization ellipticity of laser radiation, with a bandwidth that stretches from the infrared to the terahertz range. The device consists of two elements, one in front of the…
The photoconductivity of GaAs structures delta-doped by Sn has been investigated for wavelengths lambda= 650-1200 nm in the temperature interval T= 4.2-300 K. The electron densities and mobilities, before and after illumination, have been…
We report specific heat capacity measurements on a LiFeAs single crystal at temperatures down to 400 mK and magnetic fields up to 9 Tesla. A small specific heat jump at Tc and finite residual density of states at T=0 K in the…
We present a recently developed terahertz platform. An air plasma produced by an ultrashort two-color laser pulse serves as a broadband terahertz source, with electric field that has peak amplitude in the MV/cm range. Air biased coherent…
We use high-resolution chemical potential measurements to extract the entropy of monolayer and bilayer graphene in the quantum Hall regime via the Maxwell relation $\left.\frac{d\mu}{dT}\right|_N = -\left.\frac{dS}{dN}\right|_T$. Measuring…
Topological insulators (TIs) represent a novel quantum state of matter, characterized by edge or surface-states, showing up on the topological character of the bulk wave functions. Allowing electrons to move along their surface, but not…
This is a brief overview of the main physical ideas for application of field effect transistors for generation and detection of TeraHertz radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the…
We compute the jerk current tensor of GaAs, Si, and ferroelectric single-layer GeS, GeSe, SnS, and SnSe. We find peak values of the order of $10^{14}$ mA/V$^3$s$^2$ in GaAs and Si within the visible energy spectrum and an order of magnitude…
Low-temperature specific heat (SH) is measured on the 1111-type CaFe_{0.88}Co_{0.12}AsF single crystals under different magnetic fields. A clear SH jump with the height \Delta C/T|_Tc = 10.4 mJ/mol K^2 was observed at the superconducting…
We report the first coherent excitation of intramolecular vibrational modes via the nonlinear interaction of a TeraHertz (THz) light field with molecular liquids. A terahertz-terahertz-Raman pulse sequence prepares the coherences with a…
We analyze the modulation characteristics of the uncooled terahertz (THz) and infrared (IR) detectors using the variation of the density and effective temperature of the two-dimensional electron-hole plasma in uniform graphene layers (GLs)…
We have developed a single-shot terahertz time-domain spectrometer to perform optical-pump/terahertz-probe experiments in pulsed, high magnetic fields up to 30 T. The single-shot detection scheme for measuring a terahertz waveform…
Spectroscopy of discrete Landau levels (LLs) in bulk-insulating three-dimensional topological insulators (3D TIs) in perpendicular magnetic field characterizes the Dirac nature of their surface states. Despite a number of studies…
Sensitive detection of terahertz (THz) radiation is fundamental to progress in spectroscopy, advanced wireless communication, and the realization of emerging quantum technologies. However, the intrinsically low photon energies in the THz…
Using a differential technique, we have measured the specific heats of polycrystalline Ba1-xKxFe2As2 samples with x=0, 0.1 and 0.3, between 2K and 380K and in magnetic fields 0 to 13 Tesla. From this data we have determined the electronic…
Two vertical-external-cavity surface-emitting laser (VECSEL) systems producing ultraviolet (UV) radiation at 235 nm and 313 nm are demonstrated. The systems are suitable for quantum information processing applications with trapped beryllium…
We report experimental observation of an unexpectedly large thermopower in mesoscopic two-dimensional (2D) electron systems on GaAs/AlGaAs heterostructures at sub-Kelvin temperatures and zero magnetic field. Unlike conventional non-magnetic…
An apporach for the sensing of small amounts of chemical and biochemical material is presented. A frequency selective surface (FSS) made from asymmetric split ring resonators (aDSR) is excited with free space radiation. Due to interference…