Abstract In the emergent field of quantum technology, ability to manage heat at nanoscale and in cryogenic conditions is crucial for enhancing device performance terms noise, coherence, sensitivity. Here, active cooling refrigeration electron gas graphene are demonstrated, by taking advantage superconducting tunnel contacts able pump or extract directly from electrons device. These structures achieved a top ∼15.5 mK bath temperature ∼448 mK, demonstrating viability proposed architecture....

We demonstrate rapid deterministic (seeded) growth of large single-crystals graphene by chemical vapour deposition (CVD) utilising pre-patterned copper substrates with chromium nucleation sites. Arrays as several hundred microns are grown a periodicity up to 1 mm. The is transferred target using aligned and contamination- free semi-dry transfer. high quality the synthesised confirmed Raman spectroscopy transport measurements, demonstrating room-temperature carrier mobility 21 000 cm2 V−1 s−1...

We report on room temperature THz detection by means of antenna-coupled field effect transistors fabricated using epitaxial graphene grown silicon carbide substrate. Two independent mechanisms are found: plasma wave assisted-detection and thermoelectric effect, which is ascribed to the presence junctions along FET channel. The superposition calculated functional dependence both plasmonic photovoltages gate bias qualitatively well reproduces measured photovoltages. Additionally, sign reversal...

The lack of a dipolar second‐order susceptibility (χ (2) ) in silicon due to the centrosymmetry its diamond lattice usually inhibits efficient nonlinear optical processes bulk. Recently, deposition stressed nitride layers and corresponding inhomogeneous strain lead demonstration second harmonic generation electro‐optic modulation strained waveguides. However, respective impact stress/strain gradient involved interfaces is not clear. Here, influence stress stressing layer using measurements...

Abstract Recently, layered materials have become an interesting platform for quantum optics and nanophotonics. Among them, hexagonal boron nitride (hBN) has attracted a widespread interest due to its peculiar defect-related luminescence properties. In particular, the possible generation tailoring of color centers by particle irradiation are becoming pivotal aspects next photonics. this work, we use in-situ cathodoluminescence hyperspectral analysis investigate effect fast-scanning,...

A patterned-growth, scalable fabrication strategy allows photodetectors with good electrical properties that show fast response red light and persistent photocurrent blue light.

Defects in the lattice are of primal importance to tune graphene chemical, thermal and electronic properties. Electron-beam irradiation is an easy method induce defects following pre-designed patterns, but no systematic study time evolution resulting available. In this paper, change over defected sites created with low-energy ($\leq 20$ keV) electron studied both experimentally via micro-Raman spectroscopy for a period $6\times 10^3$ hours through molecular dynamics simulations. During first...

We investigated the room-temperature Terahertz (THz) response as saturable absorber of turbostratic multilayer graphene grown on carbon-face silicon carbide. By employing an open-aperture z-scan method and a 2.9 THz quantum cascade laser source, 10% enhancement transparency is observed. The saturation intensity several W/cm2, mostly attributed to Pauli blocking effect in intrinsic layers. A visible increase modulation depth function number sheets was recorded consequence low nonsaturable...

Analytical formulas are derived describing the coherent absorption of light from a realistic multilayer structure composed by an optically conducting surface on supporting substrate. The model predicts two fundamental results. First, regime named perfect transparency theoretically can always be reached. Second, optical conductance extrapolated experimental data even when substrate thickness is unknown. theoretical predictions experimentally verified analyzing graphene grown silicon carbide...

Spatially selective functionalization of monolayer graphene is achieved by combining electron beam irradiation patterning with 1,3-dipolar cycloaddition azomethine ylide and shown to be reversible via focused laser irradiation-induced desorption.

Recently, hBN has become an interesting platform for quantum optics due to the peculiar defect-related luminescence properties. In this work, multicolor radiative emissions are engineered and tailored by position-controlled low-energy electron irradiation. Varying irradiation parameters, such as beam energy and/or area dose, we able induce light at different wavelengths in green–red range. particular, 10 keV 20 levels appearance of broad emission orange–red range (600–660 nm), while 15 gives...

Micro-Raman scattering experiments were performed on strained silicon waveguides designed for nonlinear optical experiments. Thin stressing nitride (Si3N4 or SiNx) cladding layers, deposited a light-guiding core layer, strain to enable χ(2), the second-order susceptibility. Different deposition treatments allow varying applied stress. The resulting are investigated by micro-Raman confocal spectroscopy waveguide facet. By modelling measured Raman shifts, local stress and extracted. Thus,...

Abstract Recently, hexagonal boron nitride (hBN) has become an interesting platform for quantum optics due to its peculiar defect-related luminescence properties. Concomitantly, hBN was established as the ideal insulating support realizing 2D materials devices, where, on contrary, defects can affect device performance. In this work, we study light emission properties of flakes obtained by mechanical exfoliation with particular focus extended generated in process. particular, tackle different...

We report on the effect of postgrowth annealing magnetic anisotropy Fe31Co69 thin epitaxial films, 1–9 nm thick, and grown GaAs(001) substrates. Hysteresis curves obtained by means magneto-optical Kerr reveal an in-plane uniaxial with easy axis typically along [110] substrate direction. The effective perpendicular constants, Kueff K⊥eff, exhibit a steep quasilinear increase temperature. Annealing 1.9-nm-thick film for 10 min at 300 °C results in from as-grown value 8.9×103 to 1.1×105 J/m3....

We investigate the nonlinear transmission of a ~280-layer turbostratic graphene sheet for near-infrared amplifier laser pulses (775 nm, Ti:sapphire laser) with duration 150-fs and 20-fs.Saturable absorption is observed in both cases, however it not very strong, amounting to ~13% transmittance change 20-fs (150-fs) at peak intensity 30 GW/cm 2 (4 ).The dependence on incident reproduced well using theoretical model time-dependent saturable absorption, where excited carriers vacate...

Electronic cooling in hybrid normal-metal--insulator--superconductor junctions is a promising technology for the manipulation of thermal loads solid-state nanosystems. One main bottlenecks efficient electronic electron-phonon coupling, as it represents leakage channel to phonon bath. Graphene two-dimensional material that exhibits weaker coupling compared standard metals. For this reason, we study electron graphene-based systems consisting graphene sheet contacted by two...

In this article we report about linear and nonlinear optical properties of intersubband cavity polariton samples, where the resonant photonic mode is a defect state in metallo-dielectric crystal slab. By tuning single geometric parameter resonator, Q-factor can reach values as large 85, with consequent cooperativity for light-matter interaction. We show that device featuring leads to sharp saturation, or even bistability, states. This dynamics occurs at crossover between weak strong coupling...

<title>Abstract</title> In the emergent field of quantum technology, ability to manage heat at nanoscale and in cryogenic conditions is crucial for enhancing device performance terms noise, coherence, sensitivity. Here, we demonstrate active cooling refrigeration electron gas graphene, by taking advantage superconductive tunnel contacts able pump or extract directly from electrons device. Our structures achieved a top graphene ∼15mK bath temperature ∼450 mK, demonstrating viability proposed...

We report on the application of an optically tunable coherent white light source, based supercontinuum generation from microstructured optical fibres, to fluorescence lifetime imaging (FLIM) microscopy and Foerster resonance energy transfer (FRET). A prototype lens monotonic longitudinal chromatic aberration is used for tuning wavelengths 400 1000 nm acts as axial monochromator, suitable fibre delivery in confocal microscopy.

In the present article we numerically investigated magneto-optical behaviour of a sub-wavelength structure composed by monolayer graphene and metallic metasurface optical resonators.Using this hybrid graphene-metal structure, large increase non-reciprocal polarization rotation can be achieved over broad range terahertz frequencies.We demonstrate that symmetry resonator geometry plays key role for performance system: in particular, increasing properties progressively enhanced.Moreover,...

Terahertz radiation is extremely suitable for various imaging applications. In real life, these range from food or pharmaceutical quality control to illegal materials human security inspections. Despite its great potential, the wide usage and commercialization of terahertz systems are still limited by lack compact technologies. The emerging graphene-based devices can efficiently contribute fill this gap, offering higher versatility, scalability, superior electronic properties compared...