A5014469933- Graphene research and applications
- Quantum and electron transport phenomena
- Plasmonic and Surface Plasmon Research
- Topological Materials and Phenomena
- Carbon Nanotubes in Composites
- Diamond and Carbon-based Materials Research
- Terahertz technology and applications
- Thermal Radiation and Cooling Technologies
- 2D Materials and Applications
- Molecular Junctions and Nanostructures
- Photonic and Optical Devices
- Strong Light-Matter Interactions
- Superconducting and THz Device Technology
- Physics of Superconductivity and Magnetism
- Atomic and Subatomic Physics Research
- Surface and Thin Film Phenomena
- Photonic Crystals and Applications
- MXene and MAX Phase Materials
- Advancements in Battery Materials
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Quantum Electrodynamics and Casimir Effect
- Advanced Semiconductor Detectors and Materials
- Nanopore and Nanochannel Transport Studies
- Silicon and Solar Cell Technologies
Research Center of Neurology
2025
National University of Singapore
2022-2025
University of Manchester
2016-2023
Brain (Germany)
2023
Massachusetts Institute of Technology
2020-2022
Henry Royce Institute
2022
Moscow Institute of Physics and Technology
2019-2021
Moscow Institute of Thermal Technology
2021
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
2021
Donostia International Physics Center
2019
Graphene hosts a unique electron system in which electron-phonon scattering is extremely weak but electron-electron collisions are sufficiently frequent to provide local equilibrium above the temperature of liquid nitrogen. Under these conditions, electrons can behave as viscous and exhibit hydrodynamic phenomena similar classical liquids. Here we report strong evidence for this transport regime. We found that doped graphene exhibits an anomalous (negative) voltage drop near...
Materials subjected to a magnetic field exhibit the Hall effect, phenomenon studied and understood in fine detail. Here we report qualitative breach of this classical behavior electron systems with high viscosity. The viscous fluid graphene is found respond non-quantizing fields by producing an electric opposite that generated effect. contribution large identified studying local voltages arise vicinity current-injecting contacts. We analyze anomaly over wide range temperatures carrier...
Viscous electron fluids have emerged recently as a new paradigm of strongly-correlated transport in solids. Here we report on direct observation the transition to this long-sought-for state matter high-mobility system graphene. Unexpectedly, flow is found be interaction-dominated but non-hydrodynamic (quasiballistic) wide temperature range, showing signatures viscous flows only at relatively high temperatures. The between two regimes characterized by sharp maximum negative resistance, probed...
Plasmons, collective oscillations of electron systems, can efficiently couple light and electric current, thus be used to create sub-wavelength photodetectors, radiation mixers, on-chip spectrometers. Despite considerable effort, it has proven challenging implement plasmonic devices operating at terahertz frequencies. The material capable meet this challenge is graphene as supports long-lived electrically-tunable plasmons. Here we demonstrate plasmon-assisted resonant detection by...
Cyclotron motion of charge carriers in metals and semiconductors leads to Landau quantization magneto-oscillatory behavior their properties. Cryogenic temperatures are usually required observe these oscillations. We show that graphene superlattices support a different type quantum oscillations do not rely on quantization. The extremely robust persist well above room temperature magnetic fields only few T. attribute this phenomenon repetitive changes the electronic structure such experience...
An energy gap can be opened in the electronic spectrum of graphene by lifting its sublattice symmetry. In bilayers, it is possible to open gaps as large 0.2 eV. However, these rarely lead a highly insulating state expected for such semiconductors at low temperatures. This long-standing puzzle usually explained charge inhomogeneity. Here we investigate spatial distributions proximity-induced superconducting currents gapped and, also, compare measurements Hall bar and Corbino geometries normal...
Graphene is considered as a promising platform for detectors of high-frequency radiation up to the terahertz (THz) range due its superior electron mobility. Previously, it has been shown that graphene field effect transistors (FETs) exhibit room temperature broadband photoresponse incoming THz radiation, thanks thermoelectric and/or plasma wave rectification. Both effects similar functional dependences on gate voltage, and therefore, was difficult disentangle these contributions in previous...
Abstract The rectification of electromagnetic waves to direct currents is a crucial process for energy harvesting, beyond-5G wireless communications, ultra-fast science, and observational astronomy. As the radiation frequency raised sub-terahertz (THz) domain, ac-to-dc conversion by conventional electronics becomes challenging requires alternative protocols. Here, we address this challenge tunnel field-effect transistors made bilayer graphene (BLG). Taking advantage BLG’s electrically...
In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy whereas filled bands underneath contribute little to conduction. Here we describe a very different regime which carrier distribution graphene and its superlattices shifted so far from equilibrium that start playing an essential role, leading critical-current behavior. The criticalities develop upon velocity of electron flow reaching velocity. Key signatures out-of-equilibrium state...
Abstract Graphene/hBN/graphene tunnel devices offer promise as sensitive mid-infrared photodetectors but the microscopic origin underlying photoresponse in them remains elusive. In this work, we investigated photocurrent generation graphene/hBN/graphene structures with localized defect states under mid-IR illumination. We demonstrate that these is proportional to second derivative of current respect bias voltage, peaking during tunneling through hBN impurity level. revealed lies change...
The possibility to tailor photoluminescence (PL) of monolayer transition metal dichalcogenides (TMDCs) using external factors such as strain, doping and environment is significant interest for optoelectronic applications. Strain in particular can be exploited a means continuously vary the bandgap. Micrometer-scale strain gradients were proposed creating 'artificial atoms' that utilize so-called exciton funneling effect work, example, condensers. Here we describe room-temperature PL emitters...
The electronic properties of graphene superlattices have attracted intense interest that was further stimulated by the recent observation novel many-body states at "magic" angles in twisted bilayer (BLG). For very small ("marginal") twist 0.1 deg, BLG has been shown to exhibit a strain-accompanied reconstruction results submicron-size triangular domains with Bernal stacking. If interlayer bias is applied open an energy gap inside domain regions making them insulating, marginally-twisted...
Graphene shows a strong promise for detection of terahertz (THz) radiation due to its high carrier mobility, compatibility with on-chip waveguides and transistors, small heat capacitance. At the same time, weak reaction graphene's physical properties on detected can be traced down absence band gap. Here, we study effect electrically-induced gap THz in graphene bilayer split-gate p-n junction. We show that induction leads simultaneous increase current voltage responsivities. operating...
Josephson junctions (JJ) are essential for superconducting quantum technologies and searches of self-conjugate quasiparticles, pivotal fault-tolerant computing. Measuring the current-phase relation (CPR) in JJ based on topological insulators (TI) can provide critical insights into unconventional phenomena these systems, such as presence Majorana bound states (MBS) nature non-reciprocal transport. However, reconstructing CPR a function magnetic field JJs has remained experimentally...
Abstract Electrically induced p − n junctions in graphene bilayer have shown superior performance for detection of sub‐terahertz radiation at cryogenic temperatures, especially upon electrical induction the bandgap E g . Still, upper limits responsivity and noise equivalent power (NEP) very large remained unknown. Here, detectors f = 0.13 THz is studied by inducing gaps up to ≈ 90 meV, a value close observed recent transport experiments. High gap achieved using high‐κ bottom hafnium dioxide...
When approaching the atomically thin limit, defects and disorder play an increasingly important role in properties of two-dimensional (2D) materials. While are generally thought to negatively affect superconductivity 2D materials, here we demonstrate contrary case oxygenation ultrathin tantalum disulfide (TaS2). Our first-principles calculations show that incorporation oxygen into TaS2 crystal lattice is energetically favorable effectively heals sulfur vacancies typically present these...
Optical nanoantennas are of great importance for photonic devices and spectroscopy due to their capability squeezing light at the nanoscale enhancing light-matter interactions. Among them, made polar crystals supporting phonon polaritons (phononic nanoantennas) exhibit highest quality factors. This is low optical losses inherent in these materials, which, however, hinder spectral tuning dielectric nature. Here, active passive ultranarrow resonances phononic realized over a wide range (≈35...
Twisted bilayer graphene (TBG) provides an example of a system in which the interplay interlayer interactions and superlattice structure impacts electron transport variety nontrivial ways gives rise to plethora interesting effects. Understanding mechanisms scattering TBG has, however, proven challenging, raising many questions about origins resistivity this system. Here we show that exhibits high-temperature magneto-oscillations originating from charge carriers between minivalleys. The...