Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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

Quantum Physics

Going gentle on mechanical quantum systems: New experimental work establishes how quantum properties of mechanical quantum systems can be measured without destroying the quantum state May 13th, 2022

New nanomechanical oscillators with record-low loss May 13th, 2022

New hardware integrates mechanical devices into quantum tech April 22nd, 2022

New quantum network shares information at a scale practical for future real-world applications: Researchers enable real-time adjustments to communication among three remote nodes in a quantum network April 22nd, 2022

News and information

Engineering piezoelectricity and strain sensitivity in CdS to promote piezocatalytic hydrogen evolution May 13th, 2022

New nanomechanical oscillators with record-low loss May 13th, 2022

Small microring array enables large complex-valued matrix multiplication May 13th, 2022

Graphene/ Graphite

Dynamic metasurfaces and metadevices empowered by graphene May 6th, 2022

Graphene-hBN breakthrough to spur new LEDs, quantum computing: Study uncovers first method for producing high-quality, wafer-scale, single-layer hexagonal boron nitride April 15th, 2022

Graphene crystals grow better under copper cover April 1st, 2022

2 Dimensional Materials

UCI scientists turn a hydrogen molecule into a quantum sensor: New technique enables precise measurement of electrostatic properties of materials April 22nd, 2022

Laboratories

New quantum network shares information at a scale practical for future real-world applications: Researchers enable real-time adjustments to communication among three remote nodes in a quantum network April 22nd, 2022

'Frustrated' nanomagnets order themselves through disorder: Interactions between alternating layers of exotic, 2D material create 'entropy-driven order' in a structured system of magnets at equilibrium April 8th, 2022

Possible Futures

Engineering piezoelectricity and strain sensitivity in CdS to promote piezocatalytic hydrogen evolution May 13th, 2022

New nanomechanical oscillators with record-low loss May 13th, 2022

Small microring array enables large complex-valued matrix multiplication May 13th, 2022

Study finds nanomedicine targeting lymph nodes key to triple negative breast cancer treatment: In mice, nanomedicine can remodel the immune microenvironment in lymph node and tumor tissue for long-term remission and lung tumor elimination in this form of metastasized breast cance May 13th, 2022

Chip Technology

Going gentle on mechanical quantum systems: New experimental work establishes how quantum properties of mechanical quantum systems can be measured without destroying the quantum state May 13th, 2022

On-Chip Photodetection: Two-dimensional material heterojunctions hetero-integration May 13th, 2022

Small microring array enables large complex-valued matrix multiplication May 13th, 2022

Rice ‘metalens’ could disrupt vacuum UV market: Solid-state nanophotonic technology could potentially replace cabinets of equipment May 6th, 2022

Quantum Computing

New error mitigation approach helps quantum computers level up: New error mitigation approach helps quantum computers level up, ASCR: Quantum computers are prone to errors that limit their usefulness in scientific research May 6th, 2022

In balance: Quantum computing needs the right combination of order and disorder: Study shows that disorder in quantum computer chips needs to be designed to perfection / Publication in ‘Nature Communications’ May 6th, 2022

New hardware integrates mechanical devices into quantum tech April 22nd, 2022

Graphene-hBN breakthrough to spur new LEDs, quantum computing: Study uncovers first method for producing high-quality, wafer-scale, single-layer hexagonal boron nitride April 15th, 2022

Nanoelectronics

The physics of a singing saw: Insights on centuries-old folk instrument is underpinned by a mathematical principle that may pave the way for high-quality resonators for sensing, electronics and more April 22nd, 2022

Eyebrow-raising: Researchers reveal why nanowires stick to each other February 11th, 2022

Visualizing temperature transport: An unexpected technique for nanoscale characterization November 19th, 2021

Leibniz Prize winner Professor Dr. Oliver G. Schmidt moves to Chemnitz University of Technology: President Professor Dr. Gerd Strohmeier refers to an 'absolute top transfer' September 10th, 2021

Discoveries

Going gentle on mechanical quantum systems: New experimental work establishes how quantum properties of mechanical quantum systems can be measured without destroying the quantum state May 13th, 2022

New nanomechanical oscillators with record-low loss May 13th, 2022

Small microring array enables large complex-valued matrix multiplication May 13th, 2022

Study finds nanomedicine targeting lymph nodes key to triple negative breast cancer treatment: In mice, nanomedicine can remodel the immune microenvironment in lymph node and tumor tissue for long-term remission and lung tumor elimination in this form of metastasized breast cance May 13th, 2022

Materials/Metamaterials

When a band falls flat: Searching for flatness in materials: International collaboration, led by DIPC and Princeton, creates a catalogue of materials that could impact quantum technologies April 1st, 2022

Studying atomic structure of aluminum alloys for manufacturing modern aircraft March 25th, 2022

Unexplored dimensions of porous metamaterials: Researchers unlock hidden potential in a long-studied group of materials March 18th, 2022

Copper doping enables safer, cost-effective hydrogen peroxide production February 11th, 2022

Announcements

Engineering piezoelectricity and strain sensitivity in CdS to promote piezocatalytic hydrogen evolution May 13th, 2022

New nanomechanical oscillators with record-low loss May 13th, 2022

Small microring array enables large complex-valued matrix multiplication May 13th, 2022

Study finds nanomedicine targeting lymph nodes key to triple negative breast cancer treatment: In mice, nanomedicine can remodel the immune microenvironment in lymph node and tumor tissue for long-term remission and lung tumor elimination in this form of metastasized breast cance May 13th, 2022

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

Lightening up the nanoscale long-wavelength optoelectronics May 13th, 2022

On-Chip Photodetection: Two-dimensional material heterojunctions hetero-integration May 13th, 2022

Development of high-durability single-atomic catalyst using industrial humidifier: Identification of the operating mechanism of cobalt-based single-atomic catalyst and development of a mass production process. Utilization for catalyst development in various fields including fuel May 13th, 2022

Engineering piezoelectricity and strain sensitivity in CdS to promote piezocatalytic hydrogen evolution May 13th, 2022

Research partnerships

University of Strathclyde and National University of Singapore to co-ordinate satellite quantum communications May 13th, 2022

Rice ‘metalens’ could disrupt vacuum UV market: Solid-state nanophotonic technology could potentially replace cabinets of equipment May 6th, 2022

New quantum network shares information at a scale practical for future real-world applications: Researchers enable real-time adjustments to communication among three remote nodes in a quantum network April 22nd, 2022

Nanoclusters self-organize into centimeter-scale hierarchical assemblies April 22nd, 2022

Quantum nanoscience

UCI scientists turn a hydrogen molecule into a quantum sensor: New technique enables precise measurement of electrostatic properties of materials April 22nd, 2022

New hardware integrates mechanical devices into quantum tech April 22nd, 2022

Could quantum technology be New Mexico’s next economic boon? Quantum New Mexico Coalition aims to establish state as national hub April 1st, 2022

New approach transports trapped ions to create entangling gates January 28th, 2022

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