Simulations of transport dynamics of systems on the brink of a metal-insulator transition

• Grant number: 21/03439-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2021
• End date: July 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Eduardo Miranda
• Grantee: Hugo Lee Ciolfi de Andrade
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Our goal in this project is the study of models of resistive switching in disordered dielectrics close to a metal-insulator transition through random resistor network models with heat diffusion. The models consist of a two-dimensional lattice of random resistors whose voltage and current distributions are obtained from the solution of Kirchhoff's circuit equations. The diffusion equation for the Joule heat and thermal contact with reservoirs is then solved as a function of time using standard finite difference methods. The temperature and electric field dependence of each resistance is described by means of deterministic or stochastic models. We aim to characterize in this fashion the dynamic I x V curves, with special focus on the formation of spatial patterns, such as filaments, and hysteresis.