GRAPHENE

Quantum materials cut closer than ever

DTU and Graphene Flagship researchers have taken the artwork of patterning nanomaterials to the following degree. Exact patterning of 2D supplies is a path to computation and storage utilizing 2D supplies, which might ship higher efficiency and far decrease energy consumption than in the present day’s know-how.

One of the vital important current discoveries inside physics and materials know-how is two-dimensional supplies resembling graphene. Graphene is stronger, smoother, lighter, and higher at conducting warmth and electrical energy than every other identified materials.

Their most unusual function is probably their programmability. By creating delicate patterns in these supplies, we are able to change their properties dramatically and probably make exactly what we want.

At DTU, scientists have labored on enhancing cutting-edge for greater than a decade in patterning 2D supplies, utilizing refined lithography machines within the 1500 m2 cleanroom facility. Their work relies in DTU’s Middle for Nanostructured Graphene, supported by the Danish Nationwide Analysis Basis and part of The Graphene Flagship.

The electron beam lithography system in DTU Nanolab can write particulars all the way down to 10 nanometers. Pc calculations can predict precisely the form and dimension of patterns within the graphene to create new kinds of electronics. They will exploit the cost of the electron and quantum properties resembling spin or valley levels of freedom, resulting in high-speed calculations with far much less energy consumption. These calculations, nonetheless, ask for increased decision than even the very best lithography programs can ship: atomic decision.

“If we actually need to unlock the treasure chest for future quantum electronics, we have to go beneath 10 nanometers and method the atomic scale,” says professor and group chief at DTU Physics, Peter Bøggild.

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And that’s excactly what the researchers have succeeded in doing.

“We confirmed in 2019 that round holes positioned with simply 12-nanometer spacing flip the semimetallic graphene right into a semiconductor. Now we all know methods to create round holes and different shapes resembling triangles, with nanometer sharp corners. Such patterns can kind electrons primarily based on their spin and create important elements for spintronics or valleytronics. The method additionally works on different 2D supplies. With these supersmall buildings, we might create very compact and electrically tunable metalenses for use in high-speed communication and biotechnology,” explains Peter Bøggild.

Razor-sharp triangle

The analysis was led by postdoc Lene Gammelgaard, an engineering graduate of DTU in 2013 who has since performed a significant function within the experimental exploration of 2D supplies at DTU:

“The trick is to put the nanomaterial hexagonal boron-nitride on high of the fabric you need to sample. You then drill holes with a selected etching recipe,” says Lene Gammelgaard, and continues:

“The etching course of we developed over the previous years down-size patterns beneath our electron beam lithography programs’ in any other case unbreakable restrict of roughly 10 nanometers. Suppose we make a round gap with a diameter of 20 nanometers; the opening within the graphene can then be downsized to 10 nanometers. Whereas if we make a triangular gap, with the spherical holes coming from the lithography system, the downsizing will make a smaller triangle with self-sharpened corners. Often, patterns get extra imperfect if you make them smaller. That is the alternative, and this permits us to recreate the buildings the theoretical predictions inform us are optimum.”

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One can e.g. produce flat digital meta-lenses — a form of super-compact optical lens that may be managed electrically at very excessive frequencies, and which in response to Lene Gammelgaard can grow to be important elements for the communication know-how and biotechnology of the longer term.

Pushing the boundaries

The opposite key particular person is a younger scholar, Dorte Danielsen. She acquired excited about nanophysics after a Ninth-grade internship in 2012, gained a spot within the closing of a nationwide science competitors for highschool college students in 2014, and pursued research in Physics and Nanotechnology beneath DTU’s honors program for elite college students.

She explains that the mechanism behind the “super-resolution” buildings remains to be not properly understood:

“We now have a number of doable explanations for this sudden etching conduct, however there may be nonetheless a lot we do not perceive. Nonetheless, it’s an thrilling and extremely helpful method for us. On the identical time, it’s excellent news for the hundreds of researchers world wide pushing the boundaries for 2D nanoelectronics and nanophotonics.”

Supported by the Unbiased Analysis Fund Denmark, throughout the METATUNE undertaking, Dorte Danielsen will proceed her work on extraordinarily sharp nanostructures. Right here, the know-how she helped develop, shall be used to create and discover optical metalenses that may be tuned electrically.

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