Fig. 2: Experimental results of thickness-dependent metal-to-insulator transition.
From: Surface triggered stabilization of metastable charge-ordered phase in SrTiO3

a A θ-2θ diffraction for the LSTO films, with varying film thicknesses, grown on the STO (001) substrate. b Reciprocal space mapping shows X-ray diffraction intensity around (103) Bragg reflections of a 20 unit cells (u.c.) thick LSTO film grown on a STO substrate. c Inverse annular bright-field STEM images of a LSTO (6 u.c.)/STO heterostructure. d Resistivity of LSTO films with varying film thicknesses as a function of temperature. The black dotted line is an extension of temperature-dependent resistivity curve, following an adiabatic small polaron hopping model (See Supplementary Note 3). e Optical conductivity spectra of the LSTO films varying with film thickness. The filled area, dotted, and solid lines are Drude, Lorentz, and Drude/Lorentz peaks, respectively. For clarity, the high energy of charge transfer excitation was removed from the optical conductivity spectra. Source data are provided as a Source Data file.