Related papers: Terahertz detection with delta-doped GaAs/AlAs mul…
A whole class of two-color experiments involves intense, short Terahertz radiation pulses. A fast detector that is sensitive and able to resolve both near-infrared and Terahertz pulses at the same time is highly desirable. Here we present…
High peak and average power free-electron lasers (FELs) in the terahertz region (THz) require small diameter, low-emittance, and high voltage electron beams. This paper presents two 1.5-2 MV, 100-200 A, thermionic cathode electron source…
We report low temperature ($T$) heat capacity ($C$) data on a multiple-quantum-well GaAs/AlGaAs sample in the quantum Hall regime. Relative to its low field magnitude, $C$ exhibits up to 10^5-fold enhancement near $\nu$=1 where Skyrmions…
Spectacular advances in heterodyne astronomy with both the Herschel Space Observatory and Stratospheric Observatory for Far Infrared Astronomy (SOFIA) have been largely due to breakthroughs in detector technology. In order to exploit the…
Integrating a thermopile with a low power operational amplifier is an effective and cost-efficient approach to obtain a high performance compact Terahertz power detector. Here we present the development of such an integrated detector,…
We report on a GaN/AlGaN quantum cascade detector operating in the terahertz spectral range. The device was grown by metal organic chemical vapor deposition on a c-sapphire substrate and relies on polar GaN/AlGaN step quantum wells. The…
Low dimensional nano-systems are promising candidates for manipulating, controlling and capturing photons with large sensitivities and low-noise. If quantum engineered to tailor the energy of the localized electrons across the desired…
We study the electrical tunability of ultrastrong light-matter interactions between a single terahertz circuit-based complementary split ring resonator (cSRR) and a two-dimensional electron gas. For this purpose, transmission spectroscopy…
III-V semiconductor mid-infrared photodetectors based on intersubband transitions hold a great potential for ultra-high-speed operation up to several hundreds of GHz. In this work we exploit a ~350nm-thick GaAs/Al0.2Ga0.8As…
Optical characterization of AlGaAs microdisk resonant cavities with a quantum dot active region is presented. Direct passive measurement of the optical loss within AlGaAs microdisk resonant structures embedded with InAs/InGaAs…
We have developed a terahertz radiation detector that measures both the amplitude and polarization of the electric field as a function of time. The device is a three-contact photoconductive receiver designed so that two orthogonal…
We describe studies on the nanoscale transport dynamics of carriers in strained AlN/GaN/AlN quantum wells: an electron-hole bilayer charge system with large difference in transport properties between the two charge layers. From electronic…
We have observed photoinduced negative optical conductivity, or gain, in the terahertz frequency range in a GaAs multiple-quantum-well structure in a strong perpendicular magnetic field at low temperatures. The gain is narrow-band: it…
Using terahertz time-domain spectroscopy, the real part of optical conductivity [$\sigma_{1}(\omega)$] of twisted bilayer graphene was obtained at different temperatures (10 -- 300 K) in the frequency range 0.3 -- 3 THz. On top of a…
We report interlayer tunneling measurements between very dilute two-dimensional GaAs hole layers. Surprisingly, the shape and temperature-dependence of the tunneling spectrum can be explained with a Fermi liquid-based tunneling model, but…
The unique optoelectronic properties of graphene [1] make it an ideal platform for a variety of photonic applications [2], including fast photodetectors [3], transparent electrodes [4], optical modulators [5], and ultra-fast lasers [6].…
We performed phase-sensitive terahertz (0.12 - 1.2 THz) transmission measurements of Ga-enriched layers in silicon. Below the superconducting transition, T_{c} = 6.7 K, we find clear signatures of the formation of a superconducting…
We report bilayer-graphene field effect transistors operating as THz broadband photodetectors based on plasma-waves excitation. By employing wide-gate geometries or buried gate configurations, we achieve a responsivity $\sim 1.2V/W (1.3…
We report on Terahertz detection by inverted band structure HgTe-based Field Effect Transistor up to room temperature. At low temperature, we show that nonlinearities of the transistor channel allows for the observation of the quantum phase…
We report a high temperature (T = 0.3K) indicator of the excitation gap $\Delta_{5/2}$ at the filling factor $ \nu=5/2$ fractional quantum Hall state in ultra-high quality AlGaAs/GaAs two-dimensional electron gases. As the lack of…