Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Quantum chains in graphene nanoribbons: Breakthrough in nanoresearch

When graphene nanoribbons contain sections of varying width, very robust new quantum states can be created in the transition zone.

CREDIT
Empa
When graphene nanoribbons contain sections of varying width, very robust new quantum states can be created in the transition zone. CREDIT Empa

Abstract:
A material that consists of atoms of a single element, but has completely different properties depend-ing on the atomic arrangement - this may sound strange, but is actually reality with graphene nano-ribbons. The ribbons, which are only a few carbon atoms wide and exactly one atom thick, have very different electronic properties depending on their shape and width: conductor, semiconductor or insu-lator. An international research team led by Empa's

Quantum chains in graphene nanoribbons: Breakthrough in nanoresearch

St. Gallen, Switzerland | Posted on August 9th, 2018

laboratory has now suc-ceeded in precisely adjusting the properties of the ribbons by specifically varying their shape. The par-ticular feature of this technology is that not only can the «usual» electronic properties mentioned above be varied - it can also be used to generate specific local quantum states.
So what's behind it? If the width of a narrow graphene nanoribbon changes, in this case from seven to nine atoms, a special zone is created at the transition: because the electronic properties of the two ar-eas differ in a special, so-called topological way, a «protected» and thus very robust new quantum state is created in the transition zone. This local electronic quantum state can now be used as a basic component to produce tailor-made semiconductors, metals or insulators - and possibly even as a component in quantum computers.

The Empa researchers under the lead of Oliver Gröning were able to show that if these ribbons are built with regularly alternating zones of different widths, a chain of interlinked quantum states with its own electronic structure is created by the numerous transitions. The exciting thing is that the electronic properties of the chain change depending on the width of the different segments. This allows them to be finely adjusted - from conductors to semiconductors with different bandgaps. This principle can be applied to many different types of transition zones - for example, from seven to eleven atoms.

«The importance of this development is also underlined by the fact that a research group at the Uni-versity of California, Berkeley, came to similar results independently of us,» said Gröning. The work of the US research team has been published in the same issue of Nature.

On the way to nanoelectronics

Based on these novel quantum chains, precise nano-transistors could be manufactured in the future - a fundamental step on the way to nanoelectronics. Whether the switching distance between the «1» state and the «0» state of the nanotransistor is actually large enough depends on the bandgap of the semiconductor - and with the new method this can be set almost at will.

In reality, however, this is not quite as simple: for the chain to have the desired electronic properties, each of the several hundred or even thousands of atoms must be in the right place. «This is based on complex, interdisciplinary research, » says Empa researcher Gröning. «Researchers from different disci-plines in Dübendorf, Mainz, Dresden, and Troy (USA) worked together - from theoretical understanding and specific knowledge of how precursor molecules have to be built and how structures on surfaces can be selectively grown to structural and electronic analysis using a scanning tunneling microscope.»

An excursion into the quantum realm

Ultrasmall transistors - and thus the next step in the further miniaturization of electronic circuits - are the obvious application possibilities here: although they are technically challenging, electronics based on nano-transistors actually work fundamentally the same as today's microelectronics. The semicon-ducting nanoribbons produced by the Empa researchers would allow transistors with a channel cross-section 1,000 times smaller than typically manufactured today. However, further possibilities can also be imagined, for example in the field of spintronics or even quantum informatics.

This is because the electronic quantum states at junctions of graphene nanoribbons of different widths can also carry a magnetic moment. This could make it possible to process information not by charge as was previously customary, but by the so-called spin - in the figurative sense the «direction of rota-tion» of the state. And the development could even go one step further. «We have observed that topological end states occur at the ends of certain quantum chains. This offers the possibility of using them as elements of so-called qubits - the complex, interlocked states in a quantum computer,» ex-plains Oliver Gröning.

Today and tomorrow, however, no quantum computer is built from nanoribbons - there is still a lot of research needed, says Gröning: «The possibility of flexibly adjusting the electronic properties through the targeted combination of individual quantum states represents a major leap for us in the production of new materials for ultra-miniaturized transistors.» The fact that these materials are stable under environmental conditions plays an important role in the development of future applications. "The further-reaching potential of the chains to create local quantum states and link them together in a targeted manner is also fascinating," Gröning continues. «Whether this potential can actually be ex-ploited for future quantum computers remains to be seen, however. It is not enough to create localized topological states in the nanoribbons - these would also have to be coupled with other materials such as superconductors in such a way that the conditions for qubits are actually met.»

####

For more information, please click here

Contacts:
Dr. Oliver Gröning

41-587-654-669

Copyright © EMPA

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

CEA-Leti Develops CMOS Process for High-Performance MicroLEDs That Could Overcome Display-Size Obstacles: New Concept Creates All-in-One RGB MicroLEDs, Eliminates Several Transfer Steps to Receiving Substrate & Boosts Performance May 16th, 2019

Laboratories

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

2D insulators with ferromagnetism are rare; researchers just identified a new one May 10th, 2019

Graphene/ Graphite

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

ZEN gets $1m grant for graphene-enhanced concrete project May 12th, 2019

2 Dimensional Materials

New way to beat the heat in electronics: Rice University lab's flexible insulator offers high strength and superior thermal conduction May 16th, 2019

From 2D to 1D: Atomically quasi '1D' wires using a carbon nanotube template: New bulk synthesis method for nanowires of molybdenum telluride for nanoelectronics April 19th, 2019

2D borophene gets a closer look: Rice, Northwestern find new ways to image, characterize unique material April 11th, 2019

Quantum Physics

Coincidence helps with quantum measurements: New method enables quantum simulations on larger systems April 22nd, 2019

Oregon scientists drill into white graphene to create artificial atoms: Patterned on a microchip and working in ambient conditions, the atoms could lead to rapid advancements in new quantum-based technology April 12th, 2019

Possible Futures

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Chip Technology

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Skoltech researchers developed new perovskite-inspired semiconductors for electronic devices May 13th, 2019

2D insulators with ferromagnetism are rare; researchers just identified a new one May 10th, 2019

Computing faster with quasi-particles May 10th, 2019

Quantum Computing

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Computing faster with quasi-particles May 10th, 2019

Coincidence helps with quantum measurements: New method enables quantum simulations on larger systems April 22nd, 2019

Nanoelectronics

From 2D to 1D: Atomically quasi '1D' wires using a carbon nanotube template: New bulk synthesis method for nanowires of molybdenum telluride for nanoelectronics April 19th, 2019

2D borophene gets a closer look: Rice, Northwestern find new ways to image, characterize unique material April 11th, 2019

Organic semiconductors: One transistor for all purposes March 22nd, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Discoveries

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

CEA-Leti Develops CMOS Process for High-Performance MicroLEDs That Could Overcome Display-Size Obstacles: New Concept Creates All-in-One RGB MicroLEDs, Eliminates Several Transfer Steps to Receiving Substrate & Boosts Performance May 16th, 2019

Materials/Metamaterials

ZEN gets $1m grant for graphene-enhanced concrete project May 12th, 2019

Computing faster with quasi-particles May 10th, 2019

Coal could yield treatment for traumatic injuries: Rice, Texas A&M, UTHealth scientists discover coal-derived ‘dots’ are effective antioxidant April 25th, 2019

Multistep self-assembly opens door to new reconfigurable materials April 19th, 2019

Announcements

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

New way to beat the heat in electronics: Rice University lab's flexible insulator offers high strength and superior thermal conduction May 16th, 2019

Research partnerships

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New Argonne coating could have big implications for lithium batteries May 14th, 2019

Sculpting Super-Fast Light Pulses: NIST Nanopillars Shape Light Precisely for Practical Applications May 3rd, 2019

Exploring New Ways to Control Thermal Radiation April 29th, 2019

Quantum nanoscience

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

2D borophene gets a closer look: Rice, Northwestern find new ways to image, characterize unique material April 11th, 2019

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project