Manipulating and probing strong correlations of condensed matter systems

• Grant number: 24/09202-0
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2024
• End date: September 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Victor Luiz Quito
• Grantee: Victor Luiz Quito
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated scholarship(s): 24/22900-8 - Floquet engineering and exact dynamics of few-level quantum systems, BP.IC

Abstract

In many condensed matter systems, neglecting the interactions among their constituents or considering them as perturbations often consists of an excellent first approximation. However, when this scenario fails, it can give rise to remarkable phases of matter. These phases of significant interest are often confined to small regions within phase diagrams, posing challenges for theoretical characterization and experimental realization. Furthermore, several such phases present ambiguous dynamic and thermodynamic responses. Hence, pursuing theoretical methods to access and unequivocally characterize these phases becomes imperative. The main goal of this project is to explore new theoretical ways to access and characterize strongly correlated phases of matter based on recent theoretical and experimental advances. To access these phases, it is highly desirable to have external knobs that allow expanding phases confined to small regions of phase diagrams, acting analogously to applying pressure or doping crystals. A novel successful knob is coupling systems with external periodic potentials, typically light. This is known as Floquet engineering. This non-equilibrium technique makes it possible to manipulate quantum systems, leading to phases whose existence is rare in equilibrium and enabling access to novel critical points. This project aims to use Floquet engineering to access and manipulate several correlated phases using non-polarized and partially polarized light in realistic models to describe materials. We will focus on quantum magnets and Kondo lattices, bringing some of their most remarkable phases closer to experimental realization. We will start with the equilibrium phase diagrams and analyze what novel terms are generated by Floquet engineering. The frequency and intensity of the light are then selected to amplify the phases we are interested in studying. We will also explore ways of avoiding heating by exploring quantum light in cavities. For probing these phases, we will leverage the advance of coherent pulses in the Terahertz regime, which puts us at the correct energy window to study these excitations. Multidimensional spectroscopy consists of pumping multiple pulses of light with arbitrary time delays. The multiple-pulse scenario allows for the quantum interference of excitations, allowing access to information hidden in single-pulse probes in the linear regime. In this project, our goal is to calculate and analyze multidimensional spectroscopy in the presence of disorder, both in metallic phases and in low-dimensional systems. We will also investigate models of frustrated magnets, aiming to disentangle the different types of emergent excitations. (AU)