Investigation of collective quantum phenomena in low-dimensional systems

• Grant number: 19/24687-1
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): February 01, 2020
• Effective date (End): March 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Julio Antonio Larrea Jimenez
• Grantee: Matheus Henry Przygocki
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/08845-3 - An investigation into topological and exotic quantum states under extreme conditions (InvestInTopQuantEx), AP.JP

Abstract

The thesis project of the Master candidate, Matheus Henry Przygocki (MS candidate) would address open questions about the role of the system dimensionality in collective quantum phenomena. In particular, this thesis project aims to find experimental evidences of how hydrodynamic flow of phonons, electron and spin correlations evolve when the system reduces its dimensionality to few atomic layers. Such experimental findings is relevant for the understanding of the physics of quantum phase transition and novel states of quantum matter which can pave an alternative route to realize a new generation of thermoelectric and spintronic materials for energy harvesting and quantum information. In order to reach our goals, we plan to investigate surface quantum states of the insulator \ch{SrTiO_3} and the semiconductor \ch{FeGa_3}. The activities of the MS candidate covers from the synthesis of thin films with thickness from decades of nanometers to few atomic layers using state-of-the-art sample preparation until the setting of new "home-built" experimental methods to measure physical properties as thermal conductivity, specific heat and Mössbauer spectroscopy. These experimental methods to be set in the Institute of Physics, University of São Paulo (IF USP) are rather innovative and not available in commercial setup yet. Therefore, we expect that this thesis project address timely experimental methods beyond the state-of-the art to uncover emergent quantum phenomena at the material surface and interface.Thin films of the insulator \ch{SrTiO_3} will be fabricated by Molecular Beam Epitaxy (MBE), which controls the atomic growth layer by layer, whereas for the thin film semiconductor \ch{FeGa_3} the rf-sputtering will be used inside the laboratories of IF USP. The fabrication of the \ch{SrTiO_3} thin films for MBE involves international collaboration with research Institutes in United States and Europe, where the MS candidate will spend an exchange mobility period. This international experience will help the MS candidate to learn new methodologies of sample preparation and characterization of physical properties, which can highlight his work performed in IF USP. We expect that the results of his Master thesis highly advance to understand the role that phonons and magnetic anisotropy in low dimensional systems play in the formation of novel quantum states with trivial and nontrivial topology. This is a relevant issue to elucidate in order to pave a new route for the realization of new generation of functional quantum materials for high-tech application. (AU)