Straintronics across Lieb-Kagome interconversion and variable transport scaling exponents

Abstract: We propose a novel protocol of low-temperature, strain-tuned re-entrant metal-insulator transition and crossover between strongly correlated line-graph lattices (Lieb and Kagome). Using a non-perturbative numerical approach, we demonstrate for the first time that an applied shear strain stabilizes a metallic phase cradled in between a gapped magnetic insulator and a gapless flat band localized insulator, facilitating the Lieb/Kagome interconversion. Our results on transport signatures exhibit variable scaling exponents for electrical resistivity and optical conductivity, providing clear evidence of non-Fermi liquid physics. We also define a strain-dependent thermal scale to quantify the crossover between the non-Fermi liquid and bad metal phases.