Jasminka Terzic

Compressive strain-induced metal–insulator transition in orthorhombic SrIrO 3 thin films

Orthorhombic SrIrO 3 is a correlated metal whose electronic properties are highly susceptible to external perturbations due to the comparable interactions of spin–orbit interaction and electronic correlation. We have investigated the electronic properties of epitaxial orthorhombic SrIrO 3 thin-films under compressive strain using transport measurements, optical absorption spectra, and magnetoresistance. The metastable, orthorhombic SrIrO 3 thin-films are synthesized on various substrates using an epi-stabilization technique. We have observed that as in-plane lattice compression is increased, the dc-resistivity (ρ) of the thin films increases by a few orders of magnitude, and the dρ/d T changes from positive to negative values. However, optical absorption spectra show Drude-like, metallic responses without an optical gap opening for all compressively strained thin films. Transport measurements under magnetic fields show negative magnetoresistance at low temperature for compressively strained thin-films. Our results suggest that weak localization is responsible for the strain-induced metal–insulator transition for the orthorhombic SrIrO 3 thin-films.

Engineering 1D Quantum Stripes from Superlattices of 2D Layered Materials.

Dimensional tunability from two dimensions to one dimension is demonstrated for the first time using an artificial superlattice method in synthesizing 1D stripes from 2D layered materials. The 1D confinement of layered Sr2 IrO4 induces distinct 1D quantum-confined electronic states, as observed from optical spectroscopy and resonant inelastic X-ray scattering. This 1D superlattice approach is generalizable to a wide range of layered materials.