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

News and information

Light-controlled nanomachine controls catalysis: A molecular motor enables the speed of chemical processes to be controlled using light impulses November 23rd, 2020

Arrowhead Pharmaceuticals Reports Fiscal 2020 Year End Results November 23rd, 2020

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

Nanosoft releases nanoCAD Plus 20 as a major update November 20th, 2020

Spintronics advances -- Controlling magnetization direction of magnetite at room temperature: Scientists develop an energy-efficient strategy to reversibly change 'spin orientation' or magnetization direction in magnetite at room temperature November 20th, 2020

2 Dimensional Materials

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Graphene/ Graphite

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Manchester group discover new family of quasiparticles in graphene-based materials: Findings to help achieve Holy Grail of 2D materials - superfast electronic devices November 13th, 2020

Quantum Physics

NIST sensor experts invent supercool mini thermometer November 17th, 2020

CCNY & partners in quantum algorithm breakthrough November 13th, 2020

Smaller than Ever—Exploring the Unusual Properties of Quantum-sized Materials November 13th, 2020

Laboratories

NIST sensor experts invent supercool mini thermometer November 17th, 2020

Possible Futures

Light-controlled nanomachine controls catalysis: A molecular motor enables the speed of chemical processes to be controlled using light impulses November 23rd, 2020

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

Nanosoft releases nanoCAD Plus 20 as a major update November 20th, 2020

Chip Technology

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Spintronics advances -- Controlling magnetization direction of magnetite at room temperature: Scientists develop an energy-efficient strategy to reversibly change 'spin orientation' or magnetization direction in magnetite at room temperature November 20th, 2020

NIST sensor experts invent supercool mini thermometer November 17th, 2020

Manchester group discover new family of quasiparticles in graphene-based materials: Findings to help achieve Holy Grail of 2D materials - superfast electronic devices November 13th, 2020

Quantum Computing

Spintronics advances -- Controlling magnetization direction of magnetite at room temperature: Scientists develop an energy-efficient strategy to reversibly change 'spin orientation' or magnetization direction in magnetite at room temperature November 20th, 2020

NIST sensor experts invent supercool mini thermometer November 17th, 2020

CCNY & partners in quantum algorithm breakthrough November 13th, 2020

A new candidate material for quantum spin liquids November 12th, 2020

Nanoelectronics

Smaller than Ever—Exploring the Unusual Properties of Quantum-sized Materials November 13th, 2020

Deca Partners with ADTEC Engineering to Enhance Adaptive Patterning™ for 2µm Chiplet Scaling October 20th, 2020

FEFU scientists are paving way for future tiny electronics and gadgets August 28th, 2020

Oriented hexagonal boron nitride foster new type of information carrier May 22nd, 2020

Discoveries

Light-controlled nanomachine controls catalysis: A molecular motor enables the speed of chemical processes to be controlled using light impulses November 23rd, 2020

New type of ultrahigh piezoelectricity in hydrogen-bonded ferroelectrics November 20th, 2020

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

Materials/Metamaterials

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Manchester group discover new family of quasiparticles in graphene-based materials: Findings to help achieve Holy Grail of 2D materials - superfast electronic devices November 13th, 2020

Smaller than Ever—Exploring the Unusual Properties of Quantum-sized Materials November 13th, 2020

Landscape to atomic scales: Researchers apply new approach to pyrite oxidation October 30th, 2020

Announcements

Light-controlled nanomachine controls catalysis: A molecular motor enables the speed of chemical processes to be controlled using light impulses November 23rd, 2020

Arrowhead Pharmaceuticals Reports Fiscal 2020 Year End Results November 23rd, 2020

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

Nanosoft releases nanoCAD Plus 20 as a major update November 20th, 2020

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

Light-controlled nanomachine controls catalysis: A molecular motor enables the speed of chemical processes to be controlled using light impulses November 23rd, 2020

New type of ultrahigh piezoelectricity in hydrogen-bonded ferroelectrics November 20th, 2020

Staying ahead of the curve with 3D curved graphene November 20th, 2020

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

Research partnerships

Industrial-strength brine, meet your kryptonite: Boron nitride coating is key ingredient in hypersaline desalination technology November 6th, 2020

Rice finds path to nanodiamond from graphene: A spot of pressure enables chemical conversion to hardened 2D material October 29th, 2020

Cicada-inspired waterproof surfaces closer to reality, researchers report October 23rd, 2020

Deca Partners with ADTEC Engineering to Enhance Adaptive Patterning™ for 2µm Chiplet Scaling October 20th, 2020

Quantum nanoscience

Improving quantum dot interactions, one layer at a time: Scientists have found a way to control an interaction between quantum dots that could lead to more efficient solar cells November 20th, 2020

NIST sensor experts invent supercool mini thermometer November 17th, 2020

CCNY & partners in quantum algorithm breakthrough November 13th, 2020

Smaller than Ever—Exploring the Unusual Properties of Quantum-sized Materials November 13th, 2020

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