A5043362809- Graphene research and applications
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Diamond and Carbon-based Materials Research
- 2D Materials and Applications
- Photonic and Optical Devices
- Physics of Superconductivity and Magnetism
- Superconducting and THz Device Technology
- Molecular Junctions and Nanostructures
- Plasmonic and Surface Plasmon Research
- Mechanical and Optical Resonators
- Advanced Fiber Laser Technologies
- Carbon Nanotubes in Composites
- Quantum Dots Synthesis And Properties
- Thermal Radiation and Cooling Technologies
- Surface and Thin Film Phenomena
- Semiconductor Quantum Structures and Devices
- Advanced Thermodynamics and Statistical Mechanics
- Advanced MEMS and NEMS Technologies
- Chalcogenide Semiconductor Thin Films
- Quantum Electrodynamics and Casimir Effect
- Perovskite Materials and Applications
- Photocathodes and Microchannel Plates
- Electronic and Structural Properties of Oxides
- Nanowire Synthesis and Applications
École Normale Supérieure - PSL
2016-2025
Sorbonne Paris Cité
2017-2025
Université Paris Sciences et Lettres
2017-2025
Université Paris Cité
2010-2025
Sorbonne Université
2010-2025
Centre National de la Recherche Scientifique
2010-2025
École Normale Supérieure
2022-2025
Laboratoire de Physique de l'ENS
2008-2024
Université Paris-Panthéon-Assas
2023
Délégation Paris 7
2018-2021
Abstract Single photon emitters (SPEs) in low-dimensional layered materials have recently gained a large interest owing to the auspicious perspectives of integration and extreme miniaturization offered by this class materials. However, accurate control both spatial location emission wavelength quantum is essentially lacking date, thus hindering further technological steps towards scalable photonic devices. Here, we evidence SPEs high purity synthetic hexagonal boron nitride (hBN) that can be...
Current implementations of quantum bits (qubits) continue to undergo too many errors be scaled into useful machines. An emerging strategy is encode information in the two meta-stable pointer states an oscillator exchanging pairs photons with its environment, a mechanism shown provide stability without inducing decoherence. Adding these increases their separation, and macroscopic bit-flip times are expected even for handful photons, range suitable implement qubit. However, previous...
In view of the extensive use hexagonal boron nitride (hBN) in 2D material electronics, it becomes important to refine its dielectric characterization terms low-field permittivity and high-field strength conductivity up breakdown voltage. The present study aims at filling this gap using DC RF transport two Au-hBN-Au capacitor series variable thickness 10--100 nm range, made large high-pressure, high-temperature (HPHT) crystals a polymer derivative ceramics (PDC) crystals. We deduce an...
Strong electric field annihilation by particle-antiparticle pair creation, also known as the Schwinger effect, is a non-perturbative prediction of quantum electrodynamics. Its experimental demonstration remains elusive, threshold fields are extremely strong and beyond current reach. Here, we propose mesoscopic variant effect in graphene, which hosts Dirac fermions with an approximate electron-hole symmetry. Using transport measurements, report on universal 1d-Schwinger conductance at...
Owing to their strong dipole moment and long coherence times, superconducting qubits have demonstrated remarkable success in hybrid quantum circuits. However, most qubit architectures are limited the GHz frequency range, severely constraining class of systems they can interact with. The fluxonium qubit, on other hand, be biased very low while being manipulated read out with standard microwave techniques. Here, we design operate a heavy an unprecedentedly transition $1.8~\mathrm{MHz}$. We...
Thanks to their narrow band gap nature and fairly high carrier mobility, HgTe nanocrystals (NCs) are of utmost interest for optoelectronics beyond the telecom window (λ > 1.55 μm). In particular, they offer an interesting cost-effective alternative well-developed InGaAs technology. However, in contrast PbS, far less work has been dedicated integration this material photodiodes. short-wave infrared region, NCs have a more p-type character than mid-wave thus promoting development new electron...
HgTe nanocrystals (NCs) enable broadly tunable infrared absorption, now commonly used to design light sensors. This material tends grow under multipodic shapes and does not present well-defined size distributions. Such point generates traps reduces the particle packing, leading a reduced mobility. It is thus highly desirable comprehensively explore effect of shape on their performance. Here, we show, using combination electron tomography tight binding simulations, that charge dissociation...
Integrated quantum photonics, with potential applications in information processing, relies on the integration of emitters into on-chip photonic circuits. Hexagonal boron nitride (hBN) is recognized as a material that compatible such implementations, owing to its relatively high refractive index and low losses visible range, together advantageous fabrication techniques. Here, we combine hBN waveguide nanofabrication recently demonstrated local generation using electron irradiation realize...
PtSe_{2} is a van der Waals material transitioning from an indirect band gap semiconductor to semimetal with increasing thickness. Its absorption threshold has been conjectured originate interband transitions. By quantitative comparison between broadband (0.8-3.0 eV) optical of high-quality exfoliated crystals and DFT ab initio simulations, we prove instead that the arises only direct This understanding allows us shed light on semiconductor-to-semimetal transition in emblematic strongly...
Frequency tunable terahertz (THz) interdigitated photoconductive antennas (PCAs) are realised by adjusting electrode spacing. An geometry allows fabrication of PCAs with small gaps and large surface area for optical excitation. The pulsed electric field emission spectra measured using THz-time domain spectroscopy (TDS). It is observed that the peak frequency emitted shifted to higher frequencies (from 0.73 1.33 THz) as gap decreases 20 2µm). Measurements in good agreement when compared...
We describe current-voltage (I-V) characteristics of alkyl-ligated gold nanocrystals ~5 nm arrays in a long screening length limit. Arrays with different alkyl ligand lengths have been prepared to tune the electronic tunnel coupling between nanocrystals. For ligands, diffusion occurs through sequential tunneling and follows activated laws, as function temperature σ∝e(-T(0)/T) electric field I∝e(-E(0)/E). better conducting arrays, i.e., small transport properties cross over cotunneling regime...
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As the field of nanocrystal-based optoelectronics matures, more advanced techniques must be developed in order to reveal electronic structure nanocrystals, particularly with device-relevant conditions. So far, most efforts have been focused on optical spectroscopy, and electrochemistry where an absolute energy reference is required. Device optimization requires probing not only pristine material but also its actual environment (i.e., surrounded by a transport layer electrode, presence...
The current understanding of physical principles governing electronic transport in graphene field effect transistors (GFETs) has reached a level where we can model quite accurately device operation and predict intrinsic frequency limits performance. In this work, use knowledge to analyze DC RF properties bottom-gated on boron nitride exhibiting pronounced velocity saturation by substrate hyperbolic phonon polariton scattering, including Dirac pinch-off effect. We demonstrate maximum...
Abstract The paradigm of graphene transistors is based on the gate modulation channel carrier density by means a local gate. This standard architecture subject to scaling limit length and further restrictions due access contact resistances impeding device performance. We propose novel design, overcoming these issues implementing additional gates underneath region which allow full control Klein barrier taking place at edge. In particular, our work demonstrates GHz operation driven independent...
We report the detection of single electrons using a Nb0.7Ti0.3N superconducting wire deposited on an oxidized silicon substrate. While it is known that this device sensitive to photons, we show also detects with kilo-electron-volt energy emitted from cathode scanning electron microscope efficiency approaching unity. The and photon map same are in good agreement. observe events outside active area device, which attribute sensitivity backscattered electrons.
Arrays of field-effect transistors are fabricated from chemical vapor deposition grown graphene (GFETs) and label-free detection DNA hybridization performed down to femtomolar concentrations. A process is developed for large-area sheets, which includes a thin Al2 O3 layer, protecting the contamination during photolithographic patterning SiOx capping biocompatibility. It enables fabrication high-quality transistor arrays, exhibiting stable close-to-zero Dirac point voltages under ambient...
Although the main loss channel of planar microwave superconducting resonators has been identified to be related an external coupling a two-level system (TLS) bath, behavior such in presence off-resonant pump yet fully understood. Alongside well-known power-dependent damping, we observe frequency shift with conspicuous maximum for intermediate power that is attributed spectrally asymmetric saturation TLSs. We derive semiclassical model describes both these effects quantitatively. The...
High-mobility hexagonal boron nitride (hBN)/graphene/hBN heterostructures are able to reach intrinsic limits of transport. Here, we investigate optoelectronic mixing, which is a demanding function combining efficient photodetection and fast carrier dynamics. Using such heterostructure embedded in coplanar waveguide, obtain record conversion efficiency about −40 dB for frequencies up 65 GHz. This performance obtained at high doping the photobolometric regime. We provide microscopic model...
High-frequency transport in the edge states of quantum spin Hall (QSH) effect has to date rarely been explored, though it could cast light on scattering mechanisms taking place therein. We here report measurement plasmon velocity topological HgTe wells both QSH and (QH) regimes, using harmonic GHz excitations phase-resolved detection. observe low velocities corresponding large transverse widths, which we ascribe prominent influence charge puddles forming vicinity channels. Together with...
Graphene is a valuable 2D platform for plasmonics as illustrated in recent THz and mid-infrared optics experiments. These high-energy plasmons however, couple to the dielectric surface modes giving rise hybrid plasmon-polariton excitations. Ultra-long wavelengths address low energy end of plasmon spectrum, GHz–THz electronic domain, where intrinsic graphene Dirac are essentially decoupled from their environment. However experiments elusive due damping by ohmic losses at frequencies. We...
Graphene quantum dots (GQDs) have recently attracted considerable attention, with appealing properties for terahertz (THz) technology. This includes the demonstration of large thermal bolometric effects in GQDs when illuminated by THz radiation. However, interaction photons Coulomb blockade regime - single electron transport remains unexplored. Here, we demonstrate ultrasensitive photoresponse to radiation (from <0.1 10 THz) a hBN-encapsulated GQD at low temperature (170 mK). We show that...