Layered materials as a platform for quantum technologies

Nature Nanotechnology, Год журнала: 2023, Номер 18(6), С. 555 - 571

Опубликована: Июнь 1, 2023

Язык: Английский

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Real-Time Diagnostics of 2D Crystal Transformations by Pulsed Laser Deposition: Controlled Synthesis of Janus WSSe Monolayers and Alloys

ACS Nano, Год журнала: 2023, Номер 17(3), С. 2472 - 2486

Опубликована: Янв. 17, 2023

Energetic processing methods such as hyperthermal implantation hold special promise to achieve the precision synthesis of metastable two-dimensional (2D) materials Janus monolayers; however, they require precise control. Here, we report a feedback approach reveal and control transformation pathways in by pulsed laser deposition (PLD) apply it investigate kinetics monolayer WS2 crystals into WSSe WSe2 Se clusters with different maximum kinetic energies (<42 eV/Se-atom) generated ablation target. Real-time Raman spectroscopy photoluminescence are used assess structure, composition, optoelectronic quality crystal is implanted well-controlled fluxes selenium for that regulated situ ICCD imaging, ion probe, diagnostics. First-principles calculations, XPS, atomic-resolution HAADF STEM imaging understand intermediate alloy compositions their vibrational modes identify pathways. The real-time measurements highly selective top-layer conversion transforms through WS2(1-x)Se2x alloys provide means adjust conditions fractional complete monolayers transition states. general demonstrates method layers or other desired structure grown PLD, addressing priority research directions adaptive

Язык: Английский

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Emergent 2D van der Waals materials photonic sources

Nanophotonics, Год журнала: 2025, Номер unknown

Опубликована: Март 10, 2025

Abstract Over the past two decades, two-dimensional (2D) van der Waals (vdW) semiconductors have garnered significant attention in field of light sources due to their unique optoelectronic properties, such as high excitonic binding energy, tunable bandgaps, and strong optical anisotropy. These properties make 2D vdW highly promising for next-generation sources, offering advantages like enhanced efficiency, wavelength tunability, polarization control. In this review, we summarize development various material-based modulation mechanisms. We first provide an overview light-emission principles that aim develop with low-power, high-efficiency. Next, discuss advances semiconductor lasers, including intralayer interlayer exciton cavity-free systems, exciton-polariton sources. then look into single-photon emission integration on-chip followed by studies on nonlinear high-order harmonic generation P-band emission. Additionally, cover advancements electrically pumped The review concludes outlook future developments

Язык: Английский

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Ultrafast exciton fluid flow in an atomically thin MoS2 semiconductor

Nature Nanotechnology, Год журнала: 2023, Номер 18(9), С. 1012 - 1019

Опубликована: Июль 31, 2023

Язык: Английский

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Transferable screened range-separated hybrid functionals for electronic and optical properties of van der Waals materials

Physical Review Materials, Год журнала: 2023, Номер 7(10)

Опубликована: Окт. 3, 2023

The accurate description of electronic properties and optical absorption spectra is a long-standing challenge for density functional theory. Recently, the introduction screened range-separated hybrid (SRSH) functionals solid-state materials has allowed calculation fundamental band gaps that are in very good agreement with many-body perturbation However, since SRSH typically tuned to reproduce bulk phases, their transferability low-dimensional structures, which experience substantially different screening than bulk, remains an open question. In this work, we explore several prototypical van der Waals materials, including transition-metal sulfides selenides, indium selenide, black phosphorus, hexagonal boron nitride. Considering monolayer these as limiting cases, show parameters can be determined systematically, using only band-edge quasiparticle energies extremal structural phases fitting targets. resulting describe both structures accuracy comparable more demanding ab initio theory (GW Bethe-Salpeter equation) approaches. Selected examples also demonstrate parameters, obtained from reference display bilayers, indicating degree independent procedure.

Язык: Английский

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Consistent Construction of the Density Matrix from Surface Hopping Trajectories

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(6), С. 2349 - 2361

Опубликована: Март 16, 2024

Proper construction of the density matrix based on surface hopping trajectories remains a difficult problem. Due to well-known overcoherence in traditional simulations, electronic wave function cannot be used directly. In this work, we propose consistent method, which takes advantage occupation active states rescale coherence calculated by functions and ensures intrinsic consistency matrix. This new trajectory analysis method can for both Tully's fewest switches (FSSH) our recently proposed branching corrected (BCSH). As benchmarked one- two-dimensional standard scattering models, approach combined with BCSH achieves highly accurate time-dependent spatial distributions adiabatic populations compared exact quantum results.

Язык: Английский

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Nonlinear Dispersion Relation and Out‐of‐Plane Second Harmonic Generation in MoSSe and WSSe Janus Monolayers

Advanced Optical Materials, Год журнала: 2023, Номер 11(19)

Опубликована: Авг. 1, 2023

Abstract Janus transition metal dichalcogenides are an emerging class of atomically thin materials with engineered broken mirror symmetry that gives rise to long‐lived dipolar excitons, Rashba splitting, and topologically protected solitons. They hold great promise as a versatile nonlinear optical platform due their broadband harmonic generation tunability, ease integration on photonic structures, nonlinearities beyond the basal crystal plane. Here, second third in MoSSe WSSe monolayers is studied. Polarization‐resolved spectroscopy used map full second‐order susceptibility tensor MoSSe, including its out‐of‐plane components. In addition, effective third‐order dispersion close exciton resonances for both measured at room cryogenic temperatures. This work sets bedrock understanding properties probing use next‐generation on‐chip multifaceted devices.

Язык: Английский

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Exciton-Exciton Interactions in Van der Waals Heterobilayers

Physical Review X, Год журнала: 2024, Номер 14(3)

Опубликована: Авг. 14, 2024

Exciton-exciton interactions are key to understanding nonlinear optical and transport phenomena in van der Waals heterobilayers, which emerged as versatile platforms study correlated electronic states. We present a combined theory-experiment of excitonic many-body effects based on first-principle band structures Coulomb interaction matrix elements. Key our approach is the explicit treatment fermionic substructure excitons dynamical screening for density-induced energy renormalization dissipation. demonstrate that dipolar blueshifts almost perfectly compensated by effects, mainly screening-induced self-energy corrections. Moreover, we identify crossover between attractive repulsive behavior at elevated exciton densities. Theoretical findings supported experimental studies spectrally narrow, mobile interlayer atomically reconstructed, h-BN-encapsulated MoSe2/WSe2 heterobilayers. Both theory experiment show scale few meV even high injection densities vicinity Mott transition. Our results revise established picture repulsion dominating exciton-exciton heterostructures open up opportunities their external design. Published American Physical Society 2024

Язык: Английский

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Dipolar many-body complexes and their interactions in stacked 2D heterobilayers

Nature Reviews Physics, Год журнала: 2024, Номер 6(7), С. 439 - 454

Опубликована: Апрель 29, 2024

Язык: Английский

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Robust Plasma‐Assisted Growth of 2D Janus Transition Metal Dichalcogenides and Their Enhanced Photoluminescent Properties

Small Methods, Год журнала: 2024, Номер unknown

Опубликована: Окт. 27, 2024

Abstract Janus transition metal dichalcogenides (TMDs) are a novel class of 2D materials with unique mirror asymmetry. Plasma‐assisted synthesis at room temperature is favored for producing TMDs due to its energy efficiency and prevention alloying. However, current methods require stringent control over growth conditions, risking defects or unintended materials. A robust plasma‐assisted (RPA) strategy introduced, incorporating built‐in tube suitable inner diameter into the system. This innovation creates mild, uniform plasma atmosphere, allowing broader variations in parameters without significantly affecting MoSSe's morphology characteristics. approach simplifies process enhances success rate TMD production. Additionally, explored enhance photoluminescence (PL) MoSSe. Releasing MoSSe from substrate annealing it removes strain unintentional doping, improving PL performance. on hexagonal boron nitride ( h ‐BN) flakes after shows 32‐fold increase intensity. Bis(trifluoromethane) sulfonimide (TFSI) treatment results remarkable 70‐fold intensity, 2.5‐fold extension exciton lifetime, quantum yield (QY) reaching up ≈31.2%. These findings provide critical insights optimizing luminescence properties materials, advancing optoelectronics.

Язык: Английский

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