Abstract The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the density electrons in transistors or switching magnetic ferroelectric order. Another possibility between metallic and insulating phases motion ions, but their speed limited slow nucleation inhomogeneous percolative growth. Here we demonstrate fast resistance a charge wave system caused pulsed current injection. As pulse travels through material, it converts...

Revealing the relaxation mechanisms of hidden states in transition metal dichalcogenides leads to control metastability.

The advancement of 3D-printing opens up a new way constructing affordable custom terahertz (THz) components due to suitable printing resolution and THz transparency polymer materials. We present calculating, designing fabricating waveplate that phase-modulates an incident beam ({\lambda}=2.14 mm) in order create predefined intensity profile the optical wavefront on distant image plane. Our calculations were performed for two distinct target intensities with use modified Gerchberg-Saxton...

Controllable switching to and from metastable states of matter using electromagnetic fields could potentially revolutionize electronic logic memory devices. Here, we investigate the effect two-dimensional strain on between a photoinduced "hidden" state stable charge-ordered in ultrathin 1T-TaS2 crystal films different substrates, photoexcited by 35 fs laser pulses. The differential contraction sample substrate shows very large negative coefficient hidden transition, implying that stability...

We report the experimental discovery of ``superluminal'' electromagnetic 2D plasma waves in response a high-quality $\mathrm{GaAs}/\mathrm{AlGaAs}$ two-dimensional electron system on dielectric substrate. measure wave spectrum samples with different density. It is established that, at large densities, there strong hybridization between and Fabry-Perot light modes. In presence perpendicular magnetic field, resonance shown to split into two modes, each corresponding particular sense circular...

From the analysis of cyclotron resonance, we experimentally obtain band structure three-dimensional topological insulator based on a HgTe thin film. Top gating was used to shift Fermi level in film, allowing us detect separate resonance modes corresponding surface states at two opposite film interfaces, bulk conduction band, and valence band. The experimental agrees reasonably well with predictions $\mathbf{k\cdot p}$ model. Due strong hybridization bands, dispersion is close parabolic broad...

Mercury telluride (HgTe) thin films with a critical thickness of 6.5 nm are predicted to possess gapless Dirac-like band structure. We report comprehensive study on gated and optically doped samples by magnetooptical spectroscopy in the THz range. The quasi-classical analysis cyclotron resonance allowed mapping dispersion Dirac charge carriers broad range electron hole doping. A smooth transition through neutrality point between holes electrons was observed. An additional peak coming from...

We report on dynamic Shubnikov–de Haas (SdH) oscillations that are measured in the optical response, subterahertz transmittance of two-dimensional systems, and reveal two distinct types oscillation nodes: “universal” nodes at integer ratios radiation cyclotron frequencies “tunable” positions sensitive to all parameters structure. The both real imaginary parts complex analyzed using a version static Lifshitz-Kosevich formula. These results demonstrate node structure SdH provides an...

We investigate the superradiance effects in three-dimensional topological insulator HgTe with conducting surface states. demonstrate that can be explained using classical electrodynamic approach. Experiments continuous-wave spectroscopy allowed us to separate energy losses system into intrinsic and radiation losses, respectively. These results are not sensitive details of band structure material.

Quantum wells (QWs) based on mercury telluride (HgTe) thin films provide a large scale of unusual physical properties starting from an insulator via two-dimensional Dirac semimetal to three-dimensional topological insulator. These result the dramatic change QW band structure with HgTe film thickness. Although being key property, these energy dispersion relations cannot be reflected in experiments due lack appropriate tools. Here we report experimental and theoretical study two quantum...

A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using diffractive phase-plate element. The phase plate was designed modified Gerchberg-Saxton iterative algorithm to encode focused the into modulation profile. complex structure fabricated from polylactic acid fused deposition modeling, common three-dimensional-printing technique. design achieves significantly simplified optical setup, consisting 0.14 THz diverging source, and scanning detector, without...

We report on dynamic Shubnikov - de Haas (SdH) oscillations that are measured in the optical response, sub terahertz transmittance of two-dimensional systems, and reveal two distinct types oscillation nodes: "universal" nodes at integer ratios radiation cyclotron frequencies "tunable" positions sensitive to all parameters structure. The both real imaginary parts complex analyzed using a version static Lifshitz-Kosevich formula. These results demonstrate node structure SdH provides an...

Spin-orbit coupling in thin HgTe quantum wells results a relativistic-like electron band structure, making it versatile solid state platform to observe and control nontrivial electrodynamic phenomena. Here we report an observation of universal terahertz (THz) transparency determined by fine-structure constant $\ensuremath{\alpha}\ensuremath{\approx}1/137$ 6.5-nm-thick layer, close the critical thickness separating phases with topologically different electronic structure. Using THz...

We investigate the effect of 2-dimensional (in-plane) strain on critical transition temperature TH from photoexcited hidden state in 1T-TaS$_2$ thin films different substrates. also measure in-plane $T_{c2}$ between nearly commensurate charge-density wave and near 200 K. In each case, is caused by differential contraction sample substrate, ranges 0.5 % compressive (CaF$_2$) to 2 tensile (sapphire). Strain appears have an opposite H NC-C transitions. shows a large negative coefficient...

Abstract A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using diffractive phase-plate element. The phase plate was designed modified Gerchberg-Saxton iterative algorithm to encode focused the into modulation profile. complex structure fabricated from polylactic acid fused deposition modeling, common three-dimensional-printing technique. design allows for significantly simplified optical setup, consisting 0.14 THz diverging source, and scanning detector,...

We report the discovery of "superluminal" electromagnetic 2D plasma waves in response a high-quality GaAs/AlGaAs two-dimensional electron system on dielectric substrate. measure wave spectrum samples with different density. It is established that at large densities, there strong hybridization between and Fabry-Perot light modes. In presence perpendicular magnetic field, resonance shown to split into two modes, each corresponding particular sense circular polarization.

Phase waveplates for THz beam shaping were developed, calculated, and implemented. Developed phase plates could be 3D-printed from commercially available polymers, which makes them affordable fully customized. These allow to widely easily manipulate shape.