Plasmonic Twistronics: Creating Skyrmion Bags by Twisting Plasmonic Skyrmion Lattices

Alapfogalmak

This research paper introduces "plasmonic twistronics," a novel method for generating complex optical fields with unique topological features by twisting plasmonic skyrmion lattices.

Kivonat

• Bibliographic Information: Schwab, J., Neuhaus, A., Dreher, P., Tsesses, S., Cohen, K., Mangold, F., ... & Giessen, H. (n.d.). Plasmonic Twistronics: Discovery of Plasmonic Skyrmion Bags.
• Research Objective: This study investigates the application of twistronics principles to plasmonic systems, aiming to create and characterize moiré skyrmion superlattices with exotic topological features.
• Methodology: The researchers employed time-resolved vector microscopy, specifically two-photon photoemission electron microscopy (2PPE-PEEM), to experimentally observe and analyze the spatiotemporal dynamics of the electric field distribution in plasmonic skyrmion lattices. They also conducted numerical simulations to validate and complement their experimental findings.
• Key Findings: The study demonstrates the successful creation of plasmonic skyrmion bags, multi-skyrmion structures with unique topological properties, by superimposing two plasmonic skyrmion lattices at specific "magic" twist angles. The size and topological charge of these skyrmion bags are shown to be controllable by adjusting the twist angle and the center of rotation between the lattices.
• Main Conclusions: This research establishes "plasmonic twistronics" as a new paradigm for manipulating electromagnetic field distributions at the nanoscale. The ability to generate and control complex topological features in optical fields, such as skyrmion bags, holds significant potential for applications in structured light-matter interaction, super-resolution microscopy, and other advanced photonic technologies.
• Significance: This work significantly advances the field of plasmonics by introducing a novel method for tailoring the topology of optical fields. The findings have implications for the development of new techniques in nano-optics, potentially leading to advancements in high-resolution imaging, optical data storage, and quantum information processing.
• Limitations and Future Research: The study primarily focuses on plasmonic skyrmion lattices with hexagonal symmetry. Future research could explore the application of plasmonic twistronics to other lattice geometries and topological quasiparticles, further expanding the possibilities for manipulating light at the nanoscale. Additionally, investigating the interaction of these engineered optical fields with matter could lead to new discoveries and applications in fields such as materials science and quantum optics.

Statisztikák

The pump pulse used in the experiment has a center wavelength of 800 nm.
This excites long-range surface plasmons with a wavelength of 780 nm.
The experiment uses a femtosecond laser with an 80 MHz repetition rate.
The skyrmion bag was observed over a range of twist angles between 11.7 and 19.3° in simulations.
The experiment confirmed the existence of a skyrmion bag at a twist angle of 13.2°.
Skyrmion bags with 1, 7, 19, 37... skyrmions can be created when the center of rotation is at a skyrmion lattice site.
Skyrmion bags with 2, 3, 4, 10, 12, and 14 skyrmions can be created by changing the center of rotation.

Idézetek

"Here, we introduce “plasmonic twistronics” that combines the tunability of moiré superlattices with the topology of skyrmion lattices to create optical fields with exotic topological features."
"Our introduction of plasmonic twistronics provides a new paradigm for generating structured light fields with complex local topology and applications in super-resolution microscopy."
"Plasmonic twistronics provides an avenue for creating electric field distributions with novel and robust topological configurations, with arbitrary large topological invariants – a longstanding goal in the budding field of topological light quasiparticles."

Főbb Kivonatok

Plasmonic Twistronics: Discovery of Plasmonic Skyrmion Bags

by Julian Schwa... : arxiv.org 11-06-2024

https://arxiv.org/pdf/2411.03032.pdf

Mélyebb kérdések

How might the principles of plasmonic twistronics be applied to other types of waves, such as acoustic waves or matter waves, to create novel topological states?

The principles of plasmonic twistronics, which rely on the interference patterns generated by twisted periodic structures, can be extended to other wave systems beyond just plasmons. This is because the fundamental concept of moiré patterns and their ability to manipulate wave propagation transcends the specific physical system. Here's how it might be applied:
Acoustic Waves:

Acoustic Gratings: By creating two layered structures with periodic variations in acoustic impedance, analogous to the metallic gratings used for plasmons, one could create acoustic moiré lattices. These could be fabricated using phononic crystals, metamaterials with tailored acoustic properties, or even by modulating the properties of a medium using acoustic fields themselves.
Twisting and Interference: Introducing a twist between these acoustic gratings would lead to the formation of acoustic moiré patterns. The interference of acoustic waves within these patterns could then be used to create acoustic skyrmion bags and other topological states, similar to what is achieved with plasmonic twistronics.
Applications: This could lead to novel acoustic devices for sound manipulation, such as highly selective acoustic filters, acoustic cloaking devices, or even acoustic logic gates for information processing.
Matter Waves:

Optical Lattices: Ultracold atoms trapped in optical lattices, formed by interfering laser beams, offer a versatile platform to study matter waves. By creating two superimposed optical lattices with a relative twist, one can realize moiré superlattices for atoms.
Tunable Interactions: The interference patterns in these moiré optical lattices can be used to engineer the effective potential landscape experienced by the atoms. This allows for the creation of artificial gauge fields and the realization of topological states in ultracold atomic gases.
Quantum Simulation: Such systems could serve as powerful quantum simulators for studying exotic topological phases of matter, which are difficult to realize or probe in solid-state systems.
Key Challenges:

Wavelength Mismatch: The wavelengths of acoustic and matter waves are typically much larger than those of plasmons. This requires careful design and fabrication of the periodic structures to ensure that the moiré patterns are formed at the relevant length scales.
Material Properties: The properties of the materials used to create the acoustic or matter-wave gratings will significantly influence the wave propagation and the formation of topological states. Careful material selection and engineering are crucial.

Could the inherent periodicity of moiré patterns imposed by plasmonic twistronics limit the complexity or diversity of achievable topological configurations in the generated optical fields?

While the periodicity of moiré patterns is a defining feature, it doesn't necessarily limit the complexity or diversity of achievable topological configurations in optical fields. Here's why:

Beyond Simple Skyrmions: Plasmonic twistronics is not limited to creating only skyrmion bags. By carefully selecting the twist angle, the center of rotation, and the geometry of the initial lattices, one can generate a wide range of complex topological textures. This includes higher-order skyrmions, merons, and potentially even more exotic states yet to be discovered.
Breaking Symmetry: Introducing additional elements, such as defects or irregularities in the moiré pattern, can further enhance the complexity. These imperfections can break the inherent symmetry of the system, leading to the emergence of localized topological states with unique properties.
Dynamic Control: The optical properties of plasmonic structures can be dynamically tuned by external stimuli, such as electric fields or optical pulses. This dynamic control can be exploited to manipulate the moiré patterns in real-time, enabling the creation and annihilation of topological states on demand.
Multi-Layer Structures: Stacking multiple layers of twisted plasmonic structures opens up even more possibilities. The interplay between moiré patterns in different layers can lead to highly complex interference effects and the emergence of novel topological phases.
Limitations to Consider:

Fabrication Constraints: The ability to create complex topological configurations is ultimately limited by the precision and flexibility of the fabrication techniques used to create the plasmonic structures.
Resolution Limits: The spatial resolution of the optical characterization techniques used to probe the generated topological states also imposes a practical limit on the complexity that can be resolved and studied.

If we consider light as a fundamental building block of reality, how does manipulating its topology at the nanoscale challenge our understanding of the nature of light and its interaction with the universe?

Manipulating the topology of light at the nanoscale, as achieved with plasmonic twistronics, has profound implications for our understanding of light and its interaction with the universe:

Beyond Classical Electromagnetism: Traditional descriptions of light based on classical electromagnetism often treat it as a wave with well-defined amplitude and phase. However, topological properties of light, like skyrmions, introduce new degrees of freedom that go beyond these classical concepts. This necessitates a deeper understanding of light's fundamental nature, potentially requiring tools from topology and quantum field theory.
Light-Matter Interactions: Topological states of light carry unique angular momentum and spin properties. When such structured light interacts with matter, it can induce novel optical transitions and excitations, potentially leading to new forms of light-matter coupling and energy transfer. This could revolutionize fields like spectroscopy, photochemistry, and quantum information processing.
Exploring the Quantum Vacuum: Some theories suggest that the vacuum of space itself might possess a complex topological structure. By manipulating the topology of light, we might be able to create analogs of these vacuum structures in the lab, providing insights into the fundamental nature of spacetime and the quantum vacuum.
New Physical Phenomena: The ability to create and control topological states of light opens up avenues for discovering new physical phenomena. For example, it could lead to the observation of exotic optical effects like photonic analogs of the Aharonov-Bohm effect or the creation of synthetic magnetic fields for photons.
Philosophical Implications:

Nature of Reality: The ability to manipulate the fundamental properties of light at such a fine scale raises questions about the nature of reality itself. If we can engineer the topology of light, a fundamental constituent of our universe, does it imply a deeper level of control and programmability of the physical world?
Limits of Knowledge: As we delve deeper into the quantum realm and explore the topological properties of light, we might encounter phenomena that challenge our current understanding of physics and the limits of what we can know about the universe.
In conclusion, plasmonic twistronics and the ability to manipulate the topology of light represent a paradigm shift in our understanding of light and its interaction with matter. This emerging field has the potential to revolutionize various technologies and deepen our understanding of the fundamental laws governing the universe.