Interplay of superconductivity and interactions in multi-orbital, multivalley electronic systems

• Grant number: 23/14902-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2024
• End date: April 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Luis Gregório Godoy de Vasconcellos Dias da Silva
• Grantee: Lauro Barreto Braz
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Spin and charge fluctuations have been proposed to be the driven pairing mechanism of several unconventional superconductors, including different systems such as iron pnictides, and cuprates. The usual approach to treat these fluctuations is the zero-temperature theory of matrix-Random-Phase Approximation (matrix-RPA). Based on our previous work on the orbital- and sublattice-dependent matrix-RPA approach (taking into account long-range interactions) in magic-angle twisted bilayer (MATBG), our proposal is to apply this theory to different systems and study the robustness and consequences of the spin and charge fluctuation-driven superconductivity. We extend our previous work on MATBG using a corrected continuum model, which properly accounts for the filling dependence of the system's band structure. Also, we intend to explore our prediction of intersystem crossing superconductivity due to tuning of interaction parameters using electric gating experimental techniques. Our proposal aims to specifically studying the kagomé superconductors. Finally, we will employ a three-dimensional matrix-RPA theory to study the superconducting pairing symmetry of nickelate superconductors by comparing different non-interacting models, thereby providing a minimal low-energy model to describe these systems.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BRAZ, LAURO B.; NAG, TANAY; BLACK-SCHAFFER, ANNICA M.. Competing magnetic states on the surface of multilayer ABC-stacked graphene. PHYSICAL REVIEW B, v. 110, n. 24, p. 8-pg., 2024-12-03. (23/14902-8)