A5001336117- Graphene research and applications
- 2D Materials and Applications
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Perovskite Materials and Applications
- Molecular Junctions and Nanostructures
- Organic and Molecular Conductors Research
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- MXene and MAX Phase Materials
- Mechanical and Optical Resonators
- Surface and Thin Film Phenomena
- Boron and Carbon Nanomaterials Research
- Advanced Fiber Laser Technologies
- Fullerene Chemistry and Applications
- Physics of Superconductivity and Magnetism
- Ga2O3 and related materials
- Diamond and Carbon-based Materials Research
- Carbon Nanotubes in Composites
- Plasmonic and Surface Plasmon Research
- Chalcogenide Semiconductor Thin Films
- Machine Learning in Materials Science
- Quantum Dots Synthesis And Properties
- Strong Light-Matter Interactions
- Advanced Thermoelectric Materials and Devices
Songshan Lake Materials Laboratory
2021-2025
Max Planck Institute for the Structure and Dynamics of Matter
2017-2025
Center for Free-Electron Laser Science
2017-2024
Universität Hamburg
2017-2024
Hefei National Center for Physical Sciences at Nanoscale
2023
University of Science and Technology of China
2023
Chinese Academy of Sciences
2022
University of California, Berkeley
2021
Max Planck Society
2018-2021
University of the Basque Country
2014-2017
We have grown an atom-thin, ordered, two-dimensional multi-phase film in situ through germanium molecular beam epitaxy using a gold (111) surface as substrate. Its growth is similar to the formation of silicene layers on silver templates. One phases, forming large domains, observed scanning tunneling microscopy, shows clear, nearly flat, honeycomb structure. Thanks thorough synchrotron radiation core-level spectroscopy measurements and advanced density functional theory calculations we can...
We have systematically investigated the effect of oxidation on structural and electronic properties graphene based first-principles calculations. Energetically favorable atomic configurations building blocks are identified, which contain epoxide hydroxyl groups in close proximity with each other. Different arrangements these units yield a local-density approximation band gap over range few eV. These results suggest possibility creating tuning by varying level relative amount functional surface.
Using femtosecond time-resolved photoelectron spectroscopy we demonstrate that photoexcitation transforms monoclinic VO$_2$ quasi-instantaneously into a metal. Thereby, exclude an 80 structural bottleneck for the photoinduced electronic phase transition of VO$_2$. First-principles many-body perturbation theory calculations reveal high sensitivity bandgap to variations dynamically screened Coulomb interaction, supporting fully electronically driven isostructral insulator-to-metal transition....
Artificial post-graphene elemental 2D materials have received much attention recently. Especially, stanene, the tin analogue of graphene, is expected to be a robust topological insulator, even above room temperature. We grown epitaxial stanene on Ag(1 1 1) single crystal template and determined its crystalline structure synergetically by scanning tunneling microscopy, high-resolution synchrotron radiation photoemission spectroscopy, advanced first principles calculations. From STM images, we...
In a groundbreaking experimental advance it was recently shown that by stacking two sheets of graphene atop each other at twist angle close to one the so called "magic angles", an effective two-dimensional correlated system emerges. this kinetic energy low-energy electrons is much reduced and consequently interactions become very relevant, providing new platform into physics materials. Evidence proposed Mott insulating as well superconducting state in these highly tunable systems has spurred...
Nonlinear optical response from a van der Waals interface is modulated and enhanced in twistable boron nitride homostructures.
The 2D semiconductor of MoS2 has great potential for advanced electronics technologies beyond silicon. So far, high-quality monolayer wafers have been available and various demonstrations from individual transistors to integrated circuits also shown. In addition the monolayer, multilayers narrower band gaps but improved carrier mobilities current capacities over monolayer. However, achieving multi-layer remains a challenge. Here we report growth 4-inch via layer-by-layer epitaxy process....
Abstract Monolayer molybdenum disulfide (MoS 2 ), an emergent two-dimensional (2D) semiconductor, holds great promise for transcending the fundamental limits of silicon electronics and continue downscaling field-effect transistors. To realize its full potential high-end applications, controlled synthesis wafer-scale monolayer MoS single crystals on general commercial substrates is highly desired yet challenging. Here, we demonstrate successful epitaxial growth 2-inch single-crystal...
From density functional theory within the generalized gradient approximation we predict a structure of stanene with dumbbell units (DBs), and show that it is two-dimensional topological insulator an inverted band gap which can be tuned by compressive strain. Furthermore, propose boron nitride sheet reconstructed $(2\ifmmode\times\else\texttimes\fi{}2)$ InSb(111) surfaces are ideal substrates for experimental realization DB stanene, maintaining its nontrivial topology. Combined standard...
With first principles calculations, we predict a novel stable 2D layered structure for group VI elements Se and Te that call square selenene tellurene, respectively. They have chair-like buckled structures similar to other materials such as silicene germanene but with unit cell rather than hexagonal one. This special gives rise anisotropic band dispersions near the Fermi level can be described by generalized semi-Dirac Hamiltonian. We show considerably large gap (∼0.1 eV) opened spin-orbit...
The growth of the $\sqrt{3} \times \sqrt{3}$ reconstructed silicene on Ag substrate has been frequently observed in experiments while its atomic structure and formation mechanism is poorly understood. Here by first-principles calculations we show that constituted dumbbell units Si atoms arranged a honeycomb pattern. Our model shows excellent agreement with experimentally reported lattice constant STM image. We propose new for explaining spontaneous consequential structures from $3 3$...
Significance Micrometer-sized uniform four-layer (ABCA) rhombohedral graphene is realized by introducing a small twist angle between two bilayers of Bernal graphene. By means scanning tunneling spectroscopy we observe an extremely sharp van Hove singularity 3–5-meV half-width and correlated many-body gap 9.5 meV at neutrality, thus making twisted double-bilayer unique platform to realize electronic correlations in the absence moiré potential. Furthermore, ABCA domain walls display tunable...
Owing to their higher intrinsic electrical conductivity and chemical stability with respect oxide counterparts, nanostructured metal sulfides are expected revive materials for resistive sensor applications. Herein, we explore the gas sensing behavior of WS2 nanowire-nanoflake hybrid demonstrate excellent sensitivity (0.043 ppm-1) as well high selectivity towards H2S relative CO, NH3, H2, NO (with corresponding sensitivities 0.002, 0.0074, 0.0002, 0.0046 ppm-1, respectively). Gas response...
Recently, the twist angle between adjacent sheets of stacked van der Waals materials emerged as a new knob to engineer correlated states matter in two-dimensional heterostructures controlled manner, giving rise emergent phenomena such superconductivity or insulating states. Here, we use an ab initio based approach characterize electronic properties twisted bilayer MoS2. We report that, marked contrast graphene, slightly hole-doped MoS2 realizes strongly asymmetric px-py Hubbard model on...
The two-dimensional (2D) twisted bilayer materials with van der Waals coupling have ignited great research interests, paving a new way to explore the emergent quantum phenomena by twist degree of freedom. Generally, decreasing angle, enhanced interlayer will gradually flatten low-energy bands and isolate them two high-energy gaps at zero full filling, respectively. Although correlation topological physics in flat been intensively studied, little information is available for these emerging...
We investigate the topological properties of Floquet-engineered twisted bilayer graphene above magic angle driven by circularly polarized laser pulses. Employing a full Moir\'e-unit-cell tight-binding Hamiltonian based on first-principles electronic structure we show that band topology in bilayer, at twisting angles 1.05$^\circ$, essentially corresponds to one single-layer graphene. However, ability open topologically trivial gaps this system bias voltage between layers enables phase diagram...
The emerging field of twistronics, which harnesses the twist angle between two-dimensional materials, represents a promising route for design quantum as twist-angle-induced superlattices offer means to control topology and strong correlations. At small limit, particularly under strain, atomic relaxation prevails, emergent moir\'e superlattice encodes elusive insights into local interlayer interaction. Here we introduce metrology combined experiment-theory framework probe stacking energy...
Nanoscale charge control is a key enabling technology in plasmonics, electronic band structure engineering, and the topology of two-dimensional materials. By exploiting large electron affinity α-RuCl3, we are able to visualize quantify massive transfer at graphene/α-RuCl3 interfaces through generation charge-transfer plasmon polaritons (CPPs). We performed nanoimaging experiments on both ambient cryogenic temperatures discovered robust plasmonic features otherwise ungated undoped structures....