Engineering Electron Pathways in 2D-Topological Insulators
December 4, 2017 | CIC nanoGUNEEstimated reading time: 2 minutes
In a recent article published in Physical Review Letters researchers from CIC nanoGUNE, the Rudolf Peierls Centre for Theoretical Physics of Oxford, together with colleagues from Wuerzburg and Stanford University reported new insight into the electronic conduction and interference on 2D-topological insulators - an exotic kind of insulators that conduct only at the edge and that could be key for the development of a new generation of electronic devices.
Image caption: Schematic representation of the electronic behavior in the device described in the article. The arrows represent quantum channels where electrons propagate. Eectrons are allowed to change direction only at the central area, resulting under certain conditions in constructive interference.Schematic representation of the electronic behavior in the device described in the article. The arrows represent quantum channels where electrons propagate. Eectrons are allowed to change direction only at the central area, resulting under certain conditions in constructive interference.
For decades, insulating materials were thought to be “boring” materials from an electronics point of view, since electrons are immobile and cannot contribute to electrical conduction. Recently, a different class of insulators was proposed and experimentally found. We call them “topological insulators”, as their electronic structure can be mathematically classified to be different than the usual, boring, “trivial” insulators.
A fascinating property of topological insulators is that while remaining insulating in the bulk, they are very good conductors at the edge. At those edges, electrons travel in quantum channels in either direction, like in a two- lane highway. Also like on a highway, U-turns are forbidden: electrons on the edge cannot change direction without breaking the rules. The application of an external magnetic field lifts this prohibition and allows electrons to turn.
The recently published research, lead by Reyes Calvo, Ikerbasque Fellow at CIC nanoGUNE, and Fernando de Juan, currently at Rudolf Peierls Centre for Theoretical Physics, Oxford and joining the Donostia International Phisics Centre (DIPC) as Ikerbasque Fellow in 2018, reports the interplay of quantum edge states across a lateral junction in a HgTe quantum well, a canonical 2D topological insulator. From their results, they extract new information on the fundamental properties of topological edge states and propose strategies to fine-tune their interaction.
"In our work, we test the consequences that allowing electrons to turn have in the conduction of our devices. We also show how under certain circumstances, electrons allowed to return seem to do it in an orderly manner, as if in some kind of round-about, generating a constructive interference.", Calvo explains.
This work contributes new insight into the fundamental properties of the edge states and their conduction properties in 2D-topological insulators. This kind of proposals to control the properties and interactions of these states are key for their application in the development of a new generation of electronic devices based on quantum fundamental properties of materials.
Suggested Items
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
05/03/2024 | Nolan Johnson, I-Connect007This week’s most important news is strategic—and telling. When one puts together the IPC industry reports, we simply have to include the recent conversation with Shawn DuBravac and Tom Kastner. On the design side, check out the latest “On The Line With…” podcast featuring Brad Griffin from Cadence Design Systems, discussing SI and PI in the realm of intelligent system design.
Sypris Receives New Releases Under Electronic Warfare Program
05/03/2024 | Sypris Electronics LLCSypris Electronics, LLC, a subsidiary of Sypris Solutions, Inc., announced that it has recently received additional releases under a multi-year production contract that was first announced in 2022. The order, which provides for Sypris to begin deliveries in 2024, calls for the manufacture and test of electronic assemblies for an additional four systems to be supplied to a U.S. DOD contractor.
IMI Welcomes New CEO
05/03/2024 | IMIIntegrated Micro-Electronics, Inc. (IMI),The IMI Board of Directors announced, in a disclosure dated April 25, 2024, the appointment of Louis Sylvester Hughes, Chief Executive Officer (CEO).
Electronics Industry Sentiment Rose in April, Hitting New High
05/02/2024 | IPCApril 2024 marked the third consecutive month of sentiment growth among electronics manufacturers. When asked if they expected labor costs for hourly workers to rise over the next month, manufacturers in the United States, Mexico, and Europe predicted a five percent increase, while manufacturers in Asia predicted a slightly lower four percent increase.
LQDX Divests Aluminum Soldering Business - Mina™ - to Taiyo America Inc.
05/02/2024 | PRNewswireLQDX, formerly known as Averatek Corp., developer of high-performance materials for advanced semiconductor manufacturing, today announced that it has divested its aluminum soldering business – known as MinaTM – to Taiyo America Inc., a global market leader in advanced electronic materials.