Two-dimensional electron systems (2DES) subjected to a perpendicular magnetic field absorb electromagnetic radiation via cyclotron resonance (CR). Here we report a qualitative deviation from this well-known behavior. Our measurements in large-sized (10 x 10 mm2) 2DES based on GaAs and HgTe reveal that the CR-enhanced photoconductivity becomes insensitive to the radiation helicity, and shows...
We report on the superlinear behavior of direct currents induced by linearly polarized terahertz (THz) radiation in a Co/Pt magnetic metamaterial. The directed carrier movement in response to ac electric fields is commonly known as ratchet current. The sample is patterned with triangular holes forming a periodic antidot lattice. Near-field diffraction of THz radiation at the edges of the...
Terahertz time-domain spectroscopy (TDS) and its potential in the characterization of semiconductors has been demonstrated early after it had been established as a technique of measurement [1]. While TDS has successfully found its way into commercial applications in other fields such as layer thickness measurements of paints or dielectrics, it is yet to become competitive with and established...
Confining THz light into deep subwavelength cavities is the basis of many appealing prospects ranging from the control of THz light fields with metamaterials [1-3] to the potential realization of new phases of matter by engineering light-matter coupling at low energies in condensed matter systems [4-6]. Our recent work has demonstrated the possibility to confine THz light into highly...
The nonlinear optical response of the semimetal bismuth (Bi) is studied by two-dimensional terahertz (2D-THz) spectroscopy in the nonperturbative regime of light-matter interaction [1]. A pair of THz pulses with center frequencies of 1.1 THz, electric field strengths of 300 and 600 kV/cm, and pulse durations of 1 ps excites a 45-nm thick film of (111) orientated rhombohedral Bi. The two THz...
The alignment process at accelerator facilities can be time-consuming. Detectors based on field effect transistors (FETs) including photoconductive sections and are
being developed for THz (0.1 THz-10 THz) and far infrared (up to 25 THz) beamlines. They will greatly simplify and accelerate the temporal and spatial alignment
process of user experiments with a focus on pump-probe experiments...
