A5047885975- Graphene research and applications
- 2D Materials and Applications
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Perovskite Materials and Applications
- Advanced Sensor and Energy Harvesting Materials
- Ferroelectric and Piezoelectric Materials
- Acoustic Wave Resonator Technologies
- Surface and Thin Film Phenomena
- Molecular Junctions and Nanostructures
- Ferroelectric and Negative Capacitance Devices
- Plasmonic and Surface Plasmon Research
- Force Microscopy Techniques and Applications
- Quantum many-body systems
- MXene and MAX Phase Materials
- Physics of Superconductivity and Magnetism
- Near-Field Optical Microscopy
- Boron and Carbon Nanomaterials Research
- Strong Light-Matter Interactions
- Chalcogenide Semiconductor Thin Films
- Thermal properties of materials
- Quantum Dots Synthesis And Properties
- Advanced Condensed Matter Physics
- Thermal Radiation and Cooling Technologies
- Metamaterials and Metasurfaces Applications
Henry Royce Institute
2020-2025
University of Manchester
2020-2025
Institute of Radio-Engineering and Electronics
2014-2024
Moscow Institute of Physics and Technology
2017
Russian Academy of Sciences
2015
Abstract Twisted heterostructures of two-dimensional crystals offer almost unlimited scope for the design new metamaterials. Here we demonstrate a room temperature ferroelectric semiconductor that is assembled using mono- or few-layer MoS 2 . These van der Waals feature broken inversion symmetry, which, together with asymmetry atomic arrangement at interface two 2D crystals, enables domains alternating out-of-plane polarization arranged into twist-controlled network. The last can be moved by...
We apply a multiscale modeling approach to study lattice reconstruction in marginally twisted bilayers of transition metal dichalcogenides (TMD). For this, we develop DFT-parametrized interpolation formulae for interlayer adhesion energies MoSe$_2$, WSe$_2$, MoS$_2$, and WS$_2$, combine those with elasticity theory, analyze the bilayer relaxation into mesoscale domain structures. Paying particular attention inversion asymmetry TMD monolayers, show that 3R 2H stacking domains, separated by...
Ferroelectricity (Valasek, J. Phys. Rev. 1921, 17, 475), a spontaneous formation of electric polarization, is solid state phenomenon, usually, associated with ionic compounds or complex materials. Here we show that, atypically for elemental solids, few-layer graphenes can host an equilibrium out-of-plane switchable by sliding the constituent graphene sheets. The systems hosting such effect include mixed-stacking tetralayers and thicker (5–9 layers) rhombohedral graphitic films twin boundary...
Semiconducting ferroelectric materials with low energy polarization switching offer a platform for next-generation electronics such as field-effect transistors. Recently discovered interfacial ferroelectricity in bilayers of transition metal dichalcogenide films provides an opportunity to combine the potential semiconducting ferroelectrics design flexibility 2D material devices. Here, local control domains marginally twisted WS2 bilayer is demonstrated scanning tunneling microscope at room...
Abstract Van der Waals heterostructures have opened new opportunities to develop atomically thin (opto)electronic devices with a wide range of functionalities. The recent focus on manipulating the interlayer twist angle has led observation out-of-plane room temperature ferroelectricity in twisted rhombohedral bilayers transition metal dichalcogenides. Here we explore switching behaviour sliding using scanning probe microscopy domain mapping and tunnelling transport measurements. We observe...
Extensive efforts have been undertaken to combine superconductivity and the quantum Hall effect so that Cooper-pair transport between superconducting electrodes in Josephson junctions is mediated by one-dimensional edge states. This interest has motivated prospects of finding new physics, including topologically-protected quasiparticles, but also extends into metrology device applications. So far it proven challenging achieve detectable supercurrents through conductors. Here we show domain...
Twistronic van der Waals heterostrutures offer exciting opportunities for engineering optoelectronic properties of nanomaterials. Here, we use multiscale modeling to study trapping charge carriers and excitons by ferroelectric polarisation piezoelectric charges domain structures in twistronic WX$_2$/MoX$_2$ bilayers (X=S,Se). For almost aligned 2H-type bilayers, find that holes electrons are trapped the opposite -- WMo XX (tungsten over molybdenum {\it versus} overlaying chalcogens) corners...
Moiré structures in small-angle-twisted bilayers of two-dimensional (2D) semiconductors with a broken-symmetry interface form arrays ferroelectric (FE) domains periodically alternating out-of-plane polarization. Here, we propose network theory for the tunability such FE domain structure by applying an electric field perpendicular to 2D crystal. Using multiscale analysis, derive fully parametrized string-theory-like description wall (DWN) and show that it undergoes qualitative change, after...
Lattice reconstruction in twisted transition-metal dichalcogenide (TMD) bilayers gives rise to piezo- and ferroelectric moir\'e potentials for electrons holes, as well a modulation of the hybridisation across bilayer. Here, we develop hybrid $\mathbf{k}\cdot \mathbf{p}$ tight-binding models describe holes relevant valleys TMD homobilayers with parallel (P) anti-parallel (AP) orientations monolayer unit cells. We apply these superlattice effects WSe${}_2$ bilayers, conjunction microscopic...
Twisted bilayers of two-dimensional semiconductors offer a versatile platform for engineering quantum states charge carriers using moiré superlattice effects. Among the systems recent interest are twistronic MoX2/WX2 heterostructures (X = Se or S), which undergo reconstruction into preferential stacking domains and highly strained domain wall networks, determining electron/hole localization across superlattices. Here, we present catalogue options formation self-organized dots wires in...
Abstract We develop a theory for long wavelength phonons originating at dislocations separating domains in small-angle twisted homobilayers of 2D materials such as graphene and MX2 transition metal dichalcogenides (M=Mo,W; X=S,Se). find that both partial perfect dislocations, forming due to lattice relaxation the bilayers with parallel anti-parallel alignment unit cells constituent layers, respectively, support several one-dimensional subbands interdomain phonons. show spectrum lowest gapless...
We investigate interlayer adhesion and relaxation at interfaces between graphene hexagonal boron nitride (hBN) monolayers in van der Waals heterostructures. The potential hBN is calculated as a function of local lattice offset using diffusion quantum Monte Carlo methods, which provide an accurate treatment interactions. Combining the with elasticity theory, we determine relaxed structures layers interfaces, finding no metastable structures. well described by simple Lennard-Jones pair...
We investigate interlayer adhesion and relaxation at interfaces between graphene hexagonal boron nitride (hBN) monolayers in van der Waals heterostructures. The potential hBN is calculated as a function of local lattice offset using diffusion quantum Monte Carlo methods, which provide an accurate treatment interactions. Combining the with elasticity theory, we determined relaxed structures layers interfaces, finding no metastable structures. well described by simple Lennard–Jones pair...
Lattice relaxation in twistronic bilayers with close lattice parameters and almost perfect crystallographic alignment of the layers results transformation moiré pattern into a sequence preferential stacking domains domain wall networks. Here, we show that reconstructed superlattices perfectly aligned heterobilayers same chalcogen transition metal dichalcogenides have broken-symmetry structures featuring twisted nodes ("twirls") The analysis twist-angle dependence strain characteristics for...
Boundaries between structural twins of bilayer graphene (so-called AB/BA domain walls) are often discussed in terms the formation topologically protected valley-polarised chiral states.Here, we show that, depending on width boundary, latter can also support non-chiral one-dimensional (1D) states that confined to wall at low energies and take form quasi-bound higher energies, where 1D bands cross into two-dimensional spectral continuum.We present results modeling electronic properties walls...
Abstract Moiré superlattices in twistronic heterostructures are a powerful tool for materials engineering. In marginally twisted (small misalignment angle, θ ) bilayers of nearly lattice-matched two-dimensional (2D) crystals moiré patterns take the form domains commensurate stacking, separated by network domain walls (NoDW) with strain hot spots at NoDW nodes. Here, we show that, type-II transition metal dichalcogenide MoX 2 /WX (X=S, Se), hydrostatic component these creates quantum dots...
We use a hybrid $k\ifmmode\cdot\else\textperiodcentered\fi{}p$-theory--tight-binding (HkpTB) model to describe interlayer coupling simultaneously in both Bernal and twisted graphene structures. For Bernal-aligned interfaces, the HkpTB is parametrized using full Slonczewski-Weiss-McClure (SWMcC) Hamiltonian of graphite [E. McCann M. Koshino, Rep. Prog. Phys. 76, 5 (2013)], which then used refine commonly Bistritzer-MacDonald for interfaces [J. B. Lopes dos Santos et al., Rev. Lett. 99, 256802...
The creation of moir\'e superlattices in twisted bilayers two-dimensional crystals has been utilized to engineer quantum material properties graphene and transition metal dichalcogenide semiconductors. Here, we examine the structural relaxation electronic small-angle metallic ${\mathrm{NbSe}}_{2}$. Reconstruction appears be particularly strong for misalignment angles ${\ensuremath{\theta}}_{\mathrm{P}}<2.{9}^{\ensuremath{\circ}}$...
Abstract Long-period moiré superlattices at the twisted interface of van der Waals heterostructures relax into preferential stacking domains separated by dislocation networks. Here, we develop a mesoscale theory for dislocations in networks formed twistronic bilayers with parallel (P) and antiparallel (AP) alignment unit cells across interface. For P find an exact analytical displacement field partial determine analytic dependences energy per length width on orientation microscopic model...
We study the dielectric response of few layered crystals various transition metal dichalcogenides (TMDs) and hexagonal Boron Nitride (hBN). showed that out-of-plane polarizability a multilayer crystal (which characterizes to external displacement field) scales linearly with number layers, $\alpha_{zz}^{NL} =N \alpha_{zz}^{1L}$, independently stacking configuration in film. also established additivity ferroelectric polarizations consecutive interfaces case when such have broken inversion...
We develop a theory of electron tunneling accompanied by carrier-carrier scattering in graphene - insulator heterostructures. Due to the dynamic screening Coulomb interaction, scattering-aided is resonantly enhanced if transferred energy and momentum correspond those surface plasmons. reveal possible experimental manifestations such plasmon-assisted current-voltage curves plasmon emission spectra graphene-based tunnel junctions. find that inelastic current rates have sharp peaks at voltages...