Mechanical force-induced interlayer sliding in interfacial ferroelectrics

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 24, 2025

Moiré superlattices in two-dimensional stacks have attracted worldwide interest due to their unique electronic properties. A typical example is the moiré ferroelectricity, where adjacent moirés exhibit opposite spontaneous polarization that can be switched through interlayer sliding. However, contrast ideal regular ferroelectric domains (equilateral triangles) built most theoretical models, unavoidable irregular supercells (non-equilateral induced by external strain fields during transfer process been given less attention. Manipulation of controllable evolutions also a big challenge an interlinked network polarized domains. In this study, we employ sliding-disturb measurement examine and modulate these via mechanical force. By introducing curved substrate, are fabricated, three distinct types with different patterns identified modulated force disturbing. They reduced pinning forces when shear direction not aligned direction. The shift observed orthogonal This work offers effective pathway for controlled switch interfacial ferroelectricity. challenge. authors fabricate moirés, identifying patterns, modulating them

Язык: Английский

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Photocatalysis with atomically thin sheets

Chemical Society Reviews, Год журнала: 2023, Номер 52(22), С. 7687 - 7706

Опубликована: Янв. 1, 2023

Atomically thin sheets are ideal platforms for atomic-level deciphering and mastery of electronic band structures charge separation transfer. In this review, we analyze the photocatalysis occurring on atomically sheets.

Язык: Английский

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Large-Area Epitaxial Growth of Transition Metal Dichalcogenides

Chemical Reviews, Год журнала: 2024, Номер 124(17), С. 9785 - 9865

Опубликована: Авг. 12, 2024

Over the past decade, research on atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) has expanded rapidly due to their unique properties such as high carrier mobility, significant excitonic effects, and strong spin–orbit couplings. Considerable attention from both scientific industrial communities fully fueled exploration of TMDs toward practical applications. Proposed scenarios, ultrascaled transistors, on-chip photonics, flexible optoelectronics, efficient electrocatalysis, critically depend scalable production large-area TMD films. Correspondingly, substantial efforts have been devoted refining synthesizing methodology 2D TMDs, which brought field a stage that necessitates comprehensive summary. In this Review, we give systematic overview basic designs advancements in epitaxial growth TMDs. We first sketch out fundamental structures diverse properties. Subsequent discussion encompasses state-of-the-art wafer-scale designs, single-crystal strategies, techniques for structure modification postprocessing. Additionally, highlight future directions application-driven material fabrication persistent challenges, aiming inspire ongoing along revolution modern semiconductor industry.

Язык: Английский

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Ultrafast optical properties and applications of anisotropic 2D materials

Nanophotonics, Год журнала: 2024, Номер 13(2), С. 107 - 154

Опубликована: Янв. 2, 2024

Two-dimensional (2D) layered materials exhibit strong light-matter interactions, remarkable excitonic effects, and ultrafast optical response, making them promising for high-speed on-chip nanophotonics. Recently, significant attention has been directed towards anisotropic 2D (A2DMs) with low in-plane crystal symmetry. These present unique properties dependent on polarization direction, offering additional degrees of freedom absent in conventional isotropic materials. In this review, we discuss recent progress understanding the fundamental aspects nanophotonic applications A2DMs. We cover structural characteristics linear/nonlinear A2DMs, including well-studied black phosphorus rhenium dichalcogenides, as well emerging quasi-one-dimensional Then, phenomena occurring such polarization-dependent dynamics charge carriers excitons, their direction-dependent spatiotemporal diffusion, photo-induced symmetry switching, coherent acoustic phonons. Furthermore, review state-of-the-art based polarization-driven active all-optical modulations pulse generations. This concludes by perspectives challenges future prospects A2DMs

Язык: Английский

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Unidirectional Chiral Emission via Twisted Bi-layer Metasurfaces

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Ноя. 12, 2024

Controlling and channeling light emissions from unpolarized quantum dots into specific directions with chiral polarization remains a key challenge in modern photonics. Stacked metasurface designs offer potential compact solution for chirality directionality engineering. However, experimental observations of directional radiation resonant metasurfaces emitters remain obscure. In this paper, we present unidirectional emission twisted bi-layer via multi-dimensional control, including twist angle, interlayer distance, lateral displacement between the top bottom layers, as enabled by doublet alignment lithography (DAL). First, maintaining alignment, demonstrates intrinsic optical near-unity circular dichroism 0.94 reflectance difference 74%, where high greater than 0.9 persists across wide range angles −11 to 11 degrees. Second, engineered induces resonance, resulting deposited onto metasurface. Our universal platform efficient manipulation over angular range, promising applications miniaturized lasers, grating couplers, nanoantennas. Simultaneous control direction using photonic nanostructures is long-standing Here, authors experimentally demonstrate bilayer control.

Язык: Английский

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Valleytronics Meets Straintronics: Valley Fine Structure Engineering of 2D Transition Metal Dichalcogenides

Advanced Optical Materials, Год журнала: 2024, Номер 12(14)

Опубликована: Март 6, 2024

Abstract 2D transition metal dichalcogenides (TMDs) have emerged as a novel class of semiconductors with promising applications in optoelectronics, owing to their rich and tunable valley fine structure, known valleytronics. Strain engineering TMDs presents opportunities tailor structures band alignment, which greatly expands the potential investigate intrinsic properties improve device performance, thus opening new field straintronics. In this review, recent advances strain‐engineered are summarized, focus on phenomena enabled by precision tuning physics. The underlying mechanisms connections delineated between strain‐induced modifications based intravalley, intervalley, interlayer alignment single heterostructure TMDs. These insights allow targeted strain control strategies be devised for optimizing optoelectronic characteristics. This review provides perspectives guidance future directions valley‐straintronics flexible optoelectronics using TMDs, highlighting substantial promise valley‐strain fundamental physics studies well practical applications.

Язык: Английский

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Strong light-matter coupling in van der Waals materials

Light Science & Applications, Год журнала: 2024, Номер 13(1)

Опубликована: Авг. 21, 2024

In recent years, two-dimensional (2D) van der Waals materials have emerged as a focal point in research, drawing increasing attention due to their potential for isolating and synergistically combining diverse atomic layers. Atomically thin transition metal dichalcogenides (TMDs) are one of the most alluring owing exceptional electronic optical properties. The tightly bound excitons with giant oscillator strength render TMDs an ideal platform investigate strong light-matter coupling when they integrated cavities, providing wide range possibilities exploring novel polaritonic physics devices. this review, we focused on advances TMD-based coupling. foremost position, discuss various structures strongly coupled TMD materials, such Fabry-Perot photonic crystals, plasmonic nanocavities. We then present several intriguing properties relevant device applications polaritons. end, delineate promising future directions study materials.

Язык: Английский

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Beam Shaping by Stacked Nonlinear Moiré Metasurfaces

Nano Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 13, 2025

Moiré phenomena provide a versatile platform for creating tunable lattices with variable symmetries and periodicities, making them focal topic in recent photonics research. photonic devices fused metasurfaces have demonstrated numerous novel functionalities, yet fabricating moiré metasurfaces, particularly stacked configurations, poses significant challenges. In this paper, we present an innovative nanofabrication approach nonlinear using focused ion beam-assisted nanostructure transfer-welding technique. This allows precise control over interlayer twist angles, enabling complex momentum space engineering along simultaneous frequency conversion wavefront manipulation. Experimental results reveal intricate far-field second-harmonic radiation patterns, which are effectively by varying the angles. advancement addresses key fabrication challenges photonics, opening new avenues applications information processing, optical steering, switching.

Язык: Английский

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Twist-Angle-Dependent Valley Polarization of Intralayer Moiré Excitons in van der Waals Superlattices

Physical Review Letters, Год журнала: 2025, Номер 134(2)

Опубликована: Янв. 17, 2025

Twistronics, which utilizes the moiré potential to induce exotic excitations in twisted material systems, has garnered significant attention recent years. In this Letter, using Bethe-Salpeter calculations based on a continuum model of electronic structures, we explore optical characteristics intralayer excitons bilayer transition metal dichalcogenide heterostructures. We find Coulomb exchange interactions strongly influence these and degree valley polarization that splitting between spin-singlet spin-triplet can be effectively controlled by varying twist angle. Specifically, bright confined WSe_{2}/WS_{2} heterostructure achieve levels as high 90% at small angles, holds promise for future applications valleytronics. These findings underscore angle novel parameter manipulating properties excitons, thereby establishing semiconductors promising platform investigating many-body physics solid-state systems.

Язык: Английский

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Weakly Dispersive Band in Synthetic Moiré Superlattice Inducing Optimal Compact Comb Generation

Physical Review Letters, Год журнала: 2025, Номер 134(8)

Опубликована: Фев. 26, 2025

The moir\'e superlattices attract growing interest for holding exotic physics due to their fascinating properties from electronics photonics. Much attention has been focused on the localization effect waves in flat band regime or delocalization strongly dispersive feature. Here, we study weakly between two above scenarios a one-dimensional synthetic frequency superlattice and observe wave packet distributions therein toward novel comb generation. Mode spacing spectral is reduced compared free range of individual rings mode couplings unequal sublattice periods lattice. We unveil that optimal compact generation occurs simultaneously uniform power distribution broad spanning our experiment, benefiting interplay flatness uniformity distribution. Our results fundamental dimension also show new way future on-chip devices with small footprint size.

Язык: Английский

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