Home > Press > Quantum 'gruyères' for spintronics of the future: Topological insulators become a little less 'elusive'
![]() |
Abstract:
They are 'strange' materials, insulators on the inside and conductors on the surface. They also have properties that make them excellent candidates for the development of spintronics ('spin-based electronics') and more in general quantum computing. However, they are also elusive as their properties are extremely difficult to observe. Now a SISSA study, published in Physical Review Letters, proposes a new family of materials whose topological state can be directly observed experimentally, thus simplifying things for researchers.
"What interests us of topological insulators is not so much that their being insulators but that they exhibit conducting states on their surface" explains SISSA researcher Massimo Capone. "This features makes them unique, as none of the other insulating or conducting materials exhibits this dichotomy. Unfortunately, the characteristics that describe these materials are very subtle, such that they are truly difficult to identify and study". The latest paper by Capone and co-workers published in Physical Review Letters explains how such characteristics could be found in materials with more evident properties, thus simplifying research in this field and opening up new possibilities.
The mathematical explanation of why some materials are insulators and others are conductors was one of the first tangible results of the theory of quantum mechanics. Quantum mechanical models postulate that, in solids, the atoms making up the material may only have certain energy states ("positions" where the electrons spin around the nucleus) but not others. "Possible and impossible states alternate in a band pattern", explains Capone. "In insulators some bands are completely "occupied", and others are empty, whereas in conductors some empty places remain within a band". Topological insulators resemble normal insulators, with the difference that the energy states are inverted. "It's as if the bands contained artificial holes", continues Capone.
Conduction in these materials is strange for another reason as well. "The electrons contained in the energy layers have a spin, which we can think of as a direction of rotation around their axis. In a metal (a conductor), the electrons driven by an electrical field normally move in the same direction, independent of their spin, whereas in these topological insulators electrons with opposite spin propagate in opposite directions", says Adriano Amaricci, another SISSA researcher involved in the project. "This feature makes them attractive for spintronics". In fact, in electronics the information is encoded in sequences or strings of 0's and 1's, which correspond to "on" and "off" states, whereas in spintronics the 0's and 1's correspond to the type of spin, which may be only "up" or "down". Topological insulators could constitute the material basis for this alphabet.
More in detail...
The feature distinguishing topological insulators from a normal metal is very abstract and elusive. "To have an idea, try to compare this situation with the difference between a magnetic and non-magnetic state. The latter is a difference that can easily be measured", explains Amaricci.
The properties of topological insulators are instead abstract and mathematically defined, so it is difficult to know when we are dealing with such a material. "Through the use of a mathematical model and simulations, we demonstrated that new topological insulators can be found in materials that exhibit 'spectacular' features that are easily detected owing to strong electron-electron interactions" continues Amaricci. "This way, it will be easier to identify these materials experimentally, to then better investigate this important field of research".
Very important indeed, according to Capone: "the scientist who discovered these materials, in 2007, was Laurens Molenkamp who, according to rumours circulating in the research community, is a likely candidate for a future Nobel Prize". Molenkamp works at the University of Würzburg, which took part in the current study. Together with colleagues in Würzburg, and in particular Sangiovanni and Trauzettel, it might be possible to involve Molenkamp himself in the future developments of this research project.
####
For more information, please click here
Contacts:
federica sgorbissa
0039-040-378-7644
Copyright © International School of Advanced Studies (SISSA)
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.
Related News Press |
News and information
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Possible Futures
Ben-Gurion University of the Negev researchers several steps closer to harnessing patient's own T-cells to fight off cancer June 6th, 2025
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Spintronics
Quantum materials: Electron spin measured for the first time June 9th, 2023
Quantum Computing
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
Magnetism in new exotic material opens the way for robust quantum computers June 4th, 2025
Programmable electron-induced color router array May 14th, 2025
Discoveries
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Materials/Metamaterials/Magnetoresistance
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025
Announcements
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Research partnerships
HKU physicists uncover hidden order in the quantum world through deconfined quantum critical points April 25th, 2025
SMART researchers pioneer first-of-its-kind nanosensor for real-time iron detection in plants February 28th, 2025
Quantum nanoscience
Programmable electron-induced color router array May 14th, 2025
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |