Investigation of thermal transport in complex oxides towards low-dimensionality

• Grant number: 22/01742-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: October 01, 2022
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Valentina Martelli
• Grantee: Alexandre Henriques da Silva
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/19420-3 - Thermoelectricity and heat transport in topological materials, AP.JP

Abstract

In this Doctorate project, we propose to study heat transport in selected complex oxides (bulk and thin films) with the aim to experimentally investigate collective regimes of transport (as hydrodynamic flow of phonons) and possible emergence of non-trivial topological states in oxides. SrTiO3 and BaBiO3 have been selected as test-bed compounds. Bulk SrTiO3 has be shown to display Poiseuille flow of phonons, opening new questions on the role of phase and structural transitions in determining this efficient transport regime. BaBiO3 is a compound that has recently attracted attention to possibly host non-trivial topology band structure when appropriately doped, but the instability of the cubic structure leads to a trivial insulator. In this project, heat transport in SrTiO3 and BaBiO3(bulk and thin films) grown by Molecular Beam Epitaxy will be investigated implementing the 3omega technique for the experimental determination of heat transport as a functionof thickness, at the Laboratory for Quantum Matter under Extreme Conditions (IFUSP). (AU)