Bismuth Shows Novel Conducting Properties
September 12, 2018 | University of the Basque CountryEstimated reading time: 2 minutes
A team of international scientists including Maia G. Vergniory, Ikerbasque researcher at DIPC and UPV/EHU associate, have discovered a new class of materials: higher-order topological insulators. Theoretical physicists first predicted the existence of these insulators with conducting properties on the edges of crystals rather than on their surface and their characteristic ability to conduct electricity without dissipation. Now, these novel properties are demonstrated experimentally in bismuth.
Topological insulators are materials that insulate on the inside but conduct electrical current on their surface. The current flow without resistance and respond in unconventional ways to electric and magnetic fields. These unique properties are studied with real interest towards future applications in high-performance electronics and quantum computation.
Higher-Order Topological Insulators
Recently, a new class of topological materials with novel conducting properties on the edges of crystals rather than on their surface was predicted by a group of physicists from Donostia International Physics Center (DIPC), the University of the Basque Country (UPV/EHU), UZH, Princeton University and Max Planck Institute of Microstructure Physics. The new material was given the name of “higher-order topological insulator”.
According to theoretical studies, the conducting edges are extraordinarily robust for higher-order topological insulators: the current of topological electrons cannot be stopped by impurities and if the crystal breaks, the new edges automatically also conduct current. However, the most extraordinary property of these new materials is that they can in theory conduct electricity without any dissipation as superconductors do at low temperatures. This would be a specific property of higher-order class topological insulators.
Bismuth is Topological
Now, thanks to a wider scientific collaboration where scientists from Paris-Sud University and CNRS were also involved, it has been confirmed that bismuth, an element consistently described as bulk topologically trivial, follows a generalized bulk-boundary correspondence of higher-order, that is, hinges host topologically protected conducting modes instead of the surface of the crystal.
The special topological properties of this element were first identified by using symmetry arguments, topological indices, first-principles calculations, and the recently introduced framework of topological quantum chemistry.
This phenomenon was then verified experimentally. With scanning-tunneling spectroscopy, the unique signatures of the rotational symmetry of the one-dimensional states located at step edges of the crystal surface were proved. Using Josephson interferometry, scientists demonstrated their universal topological contribution to the electronic transport.
Finally, this work establishes bismuth as a higher-order topological insulator and opens the way to identify new ones.
About the University of the Basque Country
Following the motto 'Give and spread knowledge', the University of the Basque Country is a 30-year-old integrating institution willing to produce knowledge, experience and research in order to forward them to the general public.
Suggested Items
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.
Indium Corporation Expert to Present on Pb-Free Solder for Die-Attach in Discrete Power Applications
04/30/2024 | Indium CorporationIndium Corporation Product Manager – Semiconductor Dean Payne will present at the Advanced Packaging for Power Electronics conference, hosted by IMAPS, held May 8-9 in Woburn, Massachusetts, USA.
Real Time with... IPC APEX EXPO 2024: Adhesive Materials and Equipment Update with Dymax
05/01/2024 | Real Time with...IPC APEX EXPOVirginia Hogan, global business development manager at Dymax, discusses adhesive materials, dispensing and curing equipment, a new, high-reliability conformal coating, and various materials and dispensing methods.
Real Time with... IPC APEX EXPO 2024: Sustainability in the Industry
04/26/2024 | Real Time with...IPC APEX EXPOGuest Editor Henry Crandall and Chris Nash of Indium Corporation discuss the company's 90th anniversary and its focus on sustainability. They focus on the benefits of sustainable materials, their compatibility, and value propositions. The conversation also highlights how Durafuse LT technology's role in reducing reflow temperatures is leading to significant cost and energy savings. Nash also touches on downstream sustainability efforts such as using recycled materials for packaging.
SMC Korea 2024 to Highlight Semiconductor Materials Trends and Innovations on Industry’s Path to $1 Trillion
04/24/2024 | SEMIWith Korea a major consumer of semiconductor materials and advanced materials a key driver of innovation on the industry’s path to $1 trillion, industry leaders and experts will gather at SMC (Strategic Materials Conference) Korea 2024 on May 29 at the Suwon Convention Center in Gyeonggi-do, South Korea to provide insights into the latest materials developments and trends. Registration is open.