Thermoelectricity and heat transport in topological materials

• Grant number: 18/19420-3
• Support Opportunities: Research Grants - Young Investigators Grants
• Duration: January 01, 2020 - December 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Convênio/Acordo: Max Planck Society for the Advancement of Science
• Principal Investigator: Valentina Martelli
• Grantee: Valentina Martelli
• Principal researcher abroad: Steffen Wirth
• Institution abroad: Max Planck Society, Dresden, Germany
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Antonio Domingues dos Santos ; Julio Antonio Larrea Jimenez
• Associated scholarship(s): 22/01742-0 - Investigation of thermal transport in complex oxides towards low-dimensionality, BP.DD; 22/03262-5 - Thermoelectricity in topological crystalline insulators, BP.PD; 22/00992-2 - Investigation of the transport properties of the quasi-one-dimensional Bi4I4, BP.MS; + associated scholarships 21/00625-7 - Thermoelectricity and heat transport in topological Kondo Insulators, BP.DD; 21/00989-9 - Investigation of thermal transport in low-dimensional complex oxides, BP.MS; 21/00322-4 - Lead telluride: bulk and surface thermal transport at low temperature, BP.IC - associated scholarships

Abstract

Materials that host energetically low lying interactions with non-trivial topology have attracted a lot of attention due to the potential impact that the manipulation of their metallic topologically protected surface states (TSS) could bring to technological applications in spintronics and quantum computing. Recently, the interest towards the contribution of TSS to thermoelectricity has been rapidly growing, opening a new promising route in the search for best thermoelectric properties. Despite theoretical predictions having suggested possible strategies to enhance thermoelectric performance in topological materials, systematic studies under extreme conditions are carried out only infrequently; this is mainly due to the challenges that required measurement techniques involve, especially when nanostructured samples are under investigation. The goal of this project is to investigate the thermoelectric response in a number of candidate topological materials and heterostructures with the aim to bring relevant insights in the microscopic understanding of organization of charge carriers and to explore new routes for enhancing thermoelectric performance. Thermoelectricity in SmB6, PbTe, SnTe, and Ce3Bi4Pt3 compounds in both bulk and thin films will be investigated under multiple extreme conditions. Heterostructures assembled by candidate topological materials and selected magnetic thin films will be also studied to explore proximity effects and interface effects on the thermoelectric response. To reach our goals, we propose to set up at IF-USP new facilities at the state-of-the-art for the investigation of thermoelectric and thermal transport in bulk and thin film samples, under extreme conditions of low temperature (from 300K down to 0.05K) and high magnetic field (up to 20T). The grant will support the formation of an independent tandem research group (TRG) led by Valentina Martelli, associated to the Intitute of Physics of the State University of São Paulo, in cooperation with PD Dr. Wirth of the MPI-CPfS (Dresden). The project's outcomes are expected to produce outstanding scientific results thanks to the specific know-how of all participants, to the beneficial collaboration that will favour international mobility and knowledge transfer, and to the high interest towards this hot topic. The TRG can set a reference laboratory for thermoelectric and thermal transport investigation under multiple extreme conditions in Brazil and South-America. (AU)