Ground states in frustrated magnets

• Grant number: 24/08090-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: August 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Eric de Castro e Andrade
• Grantee: Elisa Torrecilha Costa Pinto
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/06629-4 - Electronic correlations in quantum materials: inhomogeneities and frustration, AP.JP2

Abstract

Geometric frustration is the inability to satisfy all local interactions simultaneously in systems of localized magnetic moments, which can lead to a large degeneracy of ground states. In this project, we want to study the paradigmatic system of magnetic frustration: the antiferromagnetic Ising model in the triangular lattice, in which frustration prevents the formation of long-range order. We want to characterize the low-temperature state by calculating its residual entropy and the spin-spin correlation function, establishing that it is, in fact, a state distinct from a paramagnet. Next, we will study what happens to this state in the presence of disturbances. In particular, we will apply an external magnetic field, which lifts the extensive degeneracy of the ground state and induces long-range order. We will combine numerical and analytical methods to uncover the rich physics of this system.