Straintronics across Lieb-Kagome interconversion and variable transport scaling exponents

TL;DR

This paper introduces a strain-tuned transition between different correlated lattice phases, revealing non-Fermi liquid behavior and a new interconversion mechanism between Lieb and Kagome lattices.

Contribution

It presents a novel low-temperature, strain-controlled protocol for phase transition and lattice interconversion, supported by non-perturbative numerical analysis.

Findings

Strain stabilizes a metallic phase between magnetic insulator and flat band insulator.

Transport exhibits variable scaling exponents indicating non-Fermi liquid physics.

Defined a thermal scale for crossover between non-Fermi liquid and bad metal phases.

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.