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Graphene confines light to one atom to enable ultra small optical switches, detectors and sensors
Next Big Future ^ | May 16, 2018 | Brian Wang

Posted on 05/16/2018 4:56:57 PM PDT by 2ndDivisionVet

Researchers have been able to confine light down to a space one atom, the smallest possible. This will pave the way to ultra-small optical switches, detectors and sensors.

Light can function as an ultra-fast communication channel, for example between different sections of a computer chip, but it can also be used for ultra-sensitive sensors or on-chip nanoscale lasers. There is currently much research into how to further shrink devices that control and guide light.

New techniques searching for ways to confine light into extremely tiny spaces, much smaller than current ones, have been on the rise. Researchers had previously found that metals can compress light below the wavelength-scale (diffraction limit), but more confinement would always come at the cost of more energy loss. This fundamental issue has now been overcome.

Science – Probing the ultimate plasmon confinement limits with a van der Waals heterostructure

“Graphene keeps surprising us: nobody thought that confining light to the one-atom limit would be possible. It will open a completely new set of applications, such as optical communications and sensing at a scale below one nanometer,” said ICREA Professor Frank Koppens at ICFO – The Institute of Photonic Sciences in Barcelona, Spain, who led the research.

This team of researchers including those from ICFO (Spain), University of Minho (Portugal) and MIT (USA) used stacks of two-dimensional materials, called heterostructures, to build up a new nano-optical device. They took a graphene monolayer (which acts as a semi-metal), and stacked onto it a hexagonal boron nitride (hBN) monolayer (an insulator), and on top of this deposited an array of metallic rods. They used graphene because it can guide light in the form of plasmons, which are oscillations of the electrons, interacting strongly with light.

“At first we were looking for a new way to excite graphene plasmons. On the way, we found that the confinement was stronger than before and the additional losses minimal. So we decided to go to the one atom limit with surprising results,” said David Alcaraz Iranzo, the lead author from ICFO.

By sending infra-red light through their devices, the researchers observed how the plasmons propagated in between the metal and the graphene. To reach the smallest space conceivable, they decided to reduce the gap between the metal and graphene as much as possible to see if the confinement of light remained efficient, i.e. without additional energy losses. Strikingly, they saw that even when a monolayer of hBN was used as a spacer, the plasmons were still excited, and could propagate freely while being confined to a channel of just one atom thick. They managed to switch this plasmon propagation on and off, simply by applying an electrical voltage, demonstrating the control of light guided in channels smaller than one nanometer.

This enables new opto-electronic devices that are just one nanometer thick, such as ultra-small optical switches, detectors and sensors. Due to the paradigm shift in optical field confinement, extreme light-matter interactions can now be explored that were not accessible before. The atom-scale toolbox of two-dimensional materials has now also proven applicable for many types of new devices where both light and electrons can be controlled even down to the scale of a nanometer.

Professor Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship, and Chair of its Management Panel, added “While the flagship is driving the development of novel applications, in particular in the field of photonics and optoelectronics, we do not lose sight of fundamental research. The impressive results reported in this paper are a testimony to the relevance for cutting edge science of the Flagship work. Having reached the ultimate limit of light confinement could lead to new devices with unprecedented small dimensions.”

Light confined to a single atomic layer The development of nanophotonic technology is reliant on the ability to confine light to spatial dimensions much less than the wavelength of the light itself. Typically, however, in metal plasmonic approaches, there is a trade-off between confinement and losses. Alcaraz Iranzo et al. fabricated heterostructures comprising monolayers of graphene and hexagonal boron nitride (hBN) and an array of metallic rods. The light was confined vertically (as propagating plasmons) between the metal and the graphene, even when the insulating hBN spacer was just a single monolayer. Such heterostructures should provide a powerful and versatile platform for nanophotonics.

Abstract The ability to confine light into tiny spatial dimensions is important for applications such as microscopy, sensing, and nanoscale lasers. Although plasmons offer an appealing avenue to confine light, Landau damping in metals imposes a trade-off between optical field confinement and losses. We show that a graphene-insulator-metal heterostructure can overcome that trade-off, and demonstrate plasmon confinement down to the ultimate limit of the length scale of one atom. This is achieved through far-field excitation of plasmon modes squeezed into an atomically thin hexagonal boron nitride dielectric spacer between graphene and metal rods. A theoretical model that takes into account the nonlocal optical response of both graphene and metal is used to describe the results. These ultraconfined plasmonic modes, addressed with far-field light excitation, enable a route to new regimes of ultrastrong light-matter interactions.


TOPICS: Business/Economy; Computers/Internet; Science
KEYWORDS: carbon; computers; graphene; grapheneoxide; graphyne; opticalcpu; quantumcomputing; science

1 posted on 05/16/2018 4:56:57 PM PDT by 2ndDivisionVet
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To: 2ndDivisionVet

This will make rework impossible.

S**tcan it, buy a new one.


2 posted on 05/16/2018 5:02:13 PM PDT by mylife (The Roar Of The Masses Could Be Farts)
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To: 2ndDivisionVet

Cue Keanu Reeves “whoa” here.


3 posted on 05/16/2018 5:04:34 PM PDT by Extremely Extreme Extremist (Democracy: The cliff's edge of Marxism)
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To: 2ndDivisionVet

Now yer IPhone can be smaller than the size of the finger up yer ***


4 posted on 05/16/2018 5:04:43 PM PDT by mylife (The Roar Of The Masses Could Be Farts)
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To: mylife

Powered by your own body’s electricity.


5 posted on 05/16/2018 5:13:17 PM PDT by BenLurkin (The above is not a statement of fact. It is either satire or opinion. Or both.)
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To: BenLurkin

Indeed, and all reporting back to the phone company!
And them to NSA!

“We’re the phone company, we don’t have to care”

Nanny Mueller Boo Boo!


6 posted on 05/16/2018 5:23:38 PM PDT by mylife (The Roar Of The Masses Could Be Farts)
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To: 2ndDivisionVet

Just wait until the enviro-warriors find out they’re using carbon.


7 posted on 05/16/2018 5:42:14 PM PDT by utahb52
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To: 2ndDivisionVet

“This will make rework impossible. S**tcan it, buy a new one.”

IC chips are already like that.

You Do all the difficult/specialized-ability function within the one component and then interface more conventionally to the outside.

This sounds like a big advance for lightpipes within an integrated/hybrid component - more optic technology added ontop of the electrics.

-

Its why generic celphones (less the battery) cost 25 cents to make (thats RF technology as well as whatever digital logic - all mostly on a single component)


8 posted on 05/16/2018 6:33:39 PM PDT by elbook
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To: elbook

Not a techie, but sounds like another gamechanger.


9 posted on 05/16/2018 6:35:54 PM PDT by 2ndDivisionVet (You cannot invade the mainland US. There'd be a rifle behind every blade of grass.)
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To: 2ndDivisionVet

Article says the same thing 6 different ways.


10 posted on 05/16/2018 6:37:37 PM PDT by Fester Chugabrew (Lock. Her. Up.)
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To: 2ndDivisionVet

Yawn. Wake me up when they’ve developed a warp drive.


11 posted on 05/16/2018 6:46:04 PM PDT by jonno (Having an opinion is not the same as having the answer...)
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To: 2ndDivisionVet; Amendment10; Bellflower; BudgieRamone; DoughtyOne; GOPJ; kosciusko51; lgjhn23; ...

This is the graphene ping list.

Click Private Reply below to join or leave this list.

Interesting: 10 Uses for Graphene.

12 posted on 05/16/2018 7:12:54 PM PDT by upchuck (Arguing w/ a woman is like reading a TOS. In the end, you ignore it all and just click "I agree.")
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To: upchuck
Graphene is a zero-gap semiconductor, because its conduction and valence bands meet at the Dirac points. The Dirac points are six locations in momentum space, on the edge of the Brillouin zone, divided into two non-equivalent sets of three points. The two sets are labeled K and K'. The sets give graphene a valley degeneracy of gv = 2. By contrast, for traditional semiconductors the primary point of interest is generally Γ, where momentum is zero. Four electronic properties separate it from other condensed matter systems
13 posted on 05/16/2018 7:19:52 PM PDT by HandyDandy ("Do you think the rain will hurt the rhubarb?")
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To: HandyDandy
What?
14 posted on 05/16/2018 7:34:15 PM PDT by upchuck (Arguing w/ a woman is like reading a TOS. In the end, you ignore it all and just click "I agree.")
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To: upchuck

Interested in your more series take on this.


15 posted on 05/16/2018 7:57:16 PM PDT by steve86 (Prophecies of Maelmhaedhoc O'Morgair (Latin form: Malachy))
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To: steve86
Interested in your more series take on this.

You're gonna be disappointed. I'm not a graphene expert. I manage the graphene ping list and enjoy reading about graphene as long as the article doesn't go over my head. This one did a little.

16 posted on 05/16/2018 8:15:45 PM PDT by upchuck (Arguing w/ a woman is like reading a TOS. In the end, you ignore it all and just click "I agree.")
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To: upchuck

One-hundred times stronger than the Man of Steel? pffft,...I doubt that.


17 posted on 05/17/2018 8:22:46 AM PDT by HandyDandy ("Do you think the rain will hurt the rhubarb?")
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