Uniaxial pressure tuning the symmetry of materials with non trivial topology

• Grant number: 20/11399-5
• Support type: Scholarships in Brazil - Master
• Effective date (Start): November 01, 2020
• Effective date (End): February 28, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Ricardo Donizeth dos Reis
• Grantee: Vinícius Estevo Silva Frehse
• Home Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovações (Brasil). Campinas , SP, Brazil
• Associated research grant: 18/00823-0 - New topological states of matter under extreme conditions, AP.JP

Abstract

The study of the topological aspects of band structure has fundamentally changed the way we understand the electronic properties of solids. Band insulators with time reversal symmetry can be classified into normal insulators (NIs), weak topological insulators (WTIs), and strong topological insulators (STIs) based on their bandgaps. Beyond the insulators we can have the gapless Dirac or Weyl semimetal phase. Besides the fundamental interest in understanding such materials, there is also the prospect of controlling their properties and putting them to use. Potential applications include efficient electrical power generation, transmission and storage; fast and secure communications. These topological phases have been intensively studied in the past decade, however the transition between these phases and the control of their exotic transport properties is less explored. Nevertheless, the precise in situ control of topological phase transition in a three-dimensional (3D) system is still an outstanding challenge. On top of that, here we propose to explore the effect of the uniaxial pressure on the crystalline structure and electron transport properties of two class of magnetic materials displaying nontrivial topology: the antiferromagnetic materials with recognized giant anomalous Hall effect Mn3X, X=Si, Ge, and the ferromagnetic TIs family Bi2X3, X=Se, Te. To obtain novel insights about the effects of pressure on the crystalline structure of the materials and be able to correlate the changes on the structure with the transport properties, we will to develop at Extreme Methods of Analysis (EMA) beamline of Sirius a new experimental setup to allow the high resolution single crystal diffraction experiments under uniaxial pressure in the exact same condition that the electronic transport experiments will be performed. The scientific results from this project will lead to a deeper understanding of the interplay between crystalline structure, electronic properties under uniaxial pressure in topological materials. Beyond the scientific goals, the development of the new instrumentation for single crystal -x-ray diffraction experiments under uniaxial pressure will open up several possibilities for material science in Brazil far beyond from the class of materials proposed in this project. (AU)