Engineering and Imaging the CDW State in Kagome Superconductors

• Grant number: 25/11191-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: March 01, 2026
• End date: February 28, 2027
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Ricardo Donizeth dos Reis
• Grantee: André Antonio Martins Chagas e Silva
• Supervisor: Chunyu Guo
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil
• Institution abroad: Max Planck Society, Hamburg, Germany
• Associated to the scholarship: 23/13723-2 - Exploring the X-ray coherence to investigate the role played by Charge Density Wave ordering on unconventional superconductors., BP.DD

Abstract

This project aims to advance the understanding of charge density wave (CDW) formation and its interplay with superconductivity in Kagome superconductors, with a focus on CsV3Sb5. While prior research has largely concentrated on symmetry-breaking phenomena, the spatial distribution and morphology of CDW domains remain poorly explored. This project will address this gap through the fabrication of state-of-the-art sample-device systems using advanced focused ion beam (FIB) techniques. These methods enable the preparation of micron-scale, strain-free lamellae with precise crystallographic alignment, as well as the controlled introduction of strain gradients for engineered inhomogeneities.A central component of the project is the integration of synchrotron-based X-ray imaging with detailed electrical transport measurements on microstructured samples. By fabricating electrical contacts precisely aligned along specific crystallographic directions, the project aims to probe anisotropic transport behaviors linked to charge density wave (CDW) ordering, nematicity, and potential timereversal symmetry breaking. Crucially, synchrotron techniques such as ptychography and nanofocused X-ray diffraction will provide real-space visualization of CDW domains, strain fields, and symmetry-breaking patterns at nanometer resolution. The ability to perform in situ electrical transport measurements simultaneously with X-ray investigations enables direct correlation between local structural dynamics and macroscopic electronic responses. Furthermore, the project will systematically explore the role of thermal quenching in modifying interlayer coupling and domain coherence, offering a comprehensive view of how external perturbations shape both the electronic and structuralproperties of these materials.The project will be conducted in collaboration with Dr. Chunyu Guo's group at the Max Planck Institute for the Structure and Dynamics of Matter, a leading laboratory in microstructuring quantum materials. The candidate will receive hands-on training in FIB sample fabrication, device preparation, and electric transport measurements. The outcomes will contribute to both the candidate's doctoral research and broader efforts to understand emergent electronic orders in Kagome superconductors.