Dark excitons allow the control of light on the nanoscale.

“Plasmonic heterostructure for dark exciton control. Credit: Jiamin Quan” (ScitechDaily, Scientists Make “Dark” Light States Shine, Unlocking New Quantum Tech)

“ Surface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric or metal–air interface. Practically, in the infrared or visible frequency. The term "surface plasmon polariton" explains that the wave involves both charge motion in the metal ("surface plasmon") and electromagnetic waves in the air or dielectric ("polariton")” (Wikipedia, Surface plasmon polariton)

“ Plasmonics or nanoplasmonics refers to the generation, detection, and manipulation of signals at optical frequencies along metal-dielectric interfaces on the nanometer scale. Inspired by photonics, plasmonics follows the trend of miniaturizing optical devices (see also nanophotonics), and finds applications in sensing, microscopy, optical communications, and bio-photonics.”(Wikipedia, plasmonics) 

Photonics means. The ability to control light on the nano- or quantum scale. The system can store information in single photons or nano-scale photon groups. The system can manipulate photons and turn them into curves. The system can use electron holes or excitons to trap the photon above the hole. Then the system can use that electron to inject data into the photon. Those energy impulses turn those photons into vertical or horizontal curves. 

An exciton is the quasiparticle where an electron starts to orbit its hole. The major problem is how to stabilize those excitons. And the answer can be in the systems called “plasmonic heterostructure”. 

“A plasmonic metamaterial is a metamaterial that uses surface plasmons to achieve optical properties not seen in nature. Plasmons are produced from the interaction of light with metal-dielectric materials. Under specific conditions, the incident light couples with the surface plasmons to create self-sustaining, propagating electromagnetic waves known as surface plasmon polaritons (SPPs). Once launched, the SPPs ripple along the metal-dielectric interface. Compared with the incident light, the SPPs can be much shorter in wavelength.” (ScitechDaily, Plasmonic metamaterial)

Above: Plasmonic structure. When another particle is below the wave. Another particle is above the wave. The wave that travels between those particles separates them from each other. 

There is a possibility of transmitting information in that system using the wave-particle interaction. In that case, the system must push the information through a wave that separates those particles. Another way would be to use particle-particle resonance interaction. The information can travel between particles. Or it can travel between waves and particles. Or just in waves. That is the reason why that thing can be used in quantum communication. 

"A plasmonic waveguide design to facilitate negative refraction in visible spectrum" (Wikipedia, Plasmonics)

"Frenkel exciton, bound electron-hole pair where the hole is localized at a position in the crystal represented by black dots" (Wikipedia, Exciton)

The plasmonic heterostructure means a composite. There are two material groups. The plasma around the material layer. Or the ionized structure. In the material itself.  

Can control those excitons. When an electron jumps out from its position. And leaves a hole behind it. The plasmonic field can make a whirl around that electron hole and deny the electron's return to that hole. Then the system can put a photon above that electron hole. 

“An exciton is a bound state of an electron and an electron hole which are attracted to each other by the electrostatic Coulomb force resulting from their opposite charges. It is an electrically neutral quasiparticle regarded as an elementary excitation primarily in condensed matter, such as insulators, semiconductors, some metals, and in some liquids. It transports energy without transporting net electric charge.” (Wikipedia, Exciton)

“A research group from the City University of New York and the University of Texas at Austin has developed a method to illuminate light states that were once undetectable, known as dark excitons, and to direct their emission with nanoscale precision. The results, reported today in Nature Photonics, point toward future technologies that could operate more quickly, take up less space, and use far less energy.” (ScitechDaily, Scientists Make “Dark” Light States Shine, Unlocking New Quantum Tech)

“Dark excitons are unusual light-matter states found in extremely thin semiconductor materials. They normally escape detection because they release light only faintly. Despite this, they are considered valuable for quantum information science and next-generation photonics because they interact with light in distinctive ways, persist for long periods, and are less affected by environmental noise, which reduces decoherence.” (ScitechDaily, Scientists Make “Dark” Light States Shine, Unlocking New Quantum Tech)

Dark excitons allow the creation of systems. Their information travels in the very weak light. If the system can use weak. Or “dark” light in data transmission, the environment covers that light. That makes it hard to detect. The problem is that. The sensor should detect that dark light. And this is why that light should be protected. 

An exciton is the quasiparticle where an electron starts to orbit its hole. The quasiparticle acts like a real particle in some situations. And that gives it the ability to control waves and photons. The exciton can control photons in two ways. The electron that orbits its hole. Can interact with those photons. So that electron hits a photon. And pushes it into a new direction. Another thing is to use the hole to control those photons. The electron hole is a lower energy point in the electromagnetic field. And that thing. It can also be used in photonic control. 

The electron hole can also act as a collector. If the system inputs energy into its edge. That quantum-size structure pulls. That energy into the middle of it. The energy forms a pike that could trap a photon around it. These kinds of phenomena can also be used in 2D materials that should withstand very high-energy impulses. Those holes can act as the quantum dots that can collect energy into them. And then the laser. Or some other beam can transport energy out from those holes. 

https://nanocomposix.com/pages/the-science-of-plasmonics

https://scitechdaily.com/scientists-make-dark-light-states-shine-unlocking-new-quantum-tech/

https://en.wikipedia.org/wiki/Exciton

https://en.wikipedia.org/wiki/Plasmonics

https://en.wikipedia.org/wiki/Plasmonic_metamaterial

https://en.wikipedia.org/wiki/Surface_plasmon_polariton