DOI: 10.20350/digitalcsic/17293
title: Dataset Figures 1 to 5 paper entitled "Stoichiometric control of electron mobility and 2D superconductivity at LaAlO3-SrTiO3 interfaces"

description: Description of the Contents of the Files Figure 1 – Structural and Stoichiometric Characterization of LAO Films. This file contains structural and chemical data for LaAlO₃ (LAO) films grown on SrTiO₃ (STO) substrates. It includes: Reflection High-Energy Electron Diffraction (RHEED) intensity oscillations and Atomic Force Microscopy (AFM) topography images confirming layer-by-layer growth and smooth surfaces. X-ray Photoelectron Spectroscopy (XPS) spectra showing La, Al, and Sr peaks, used to calculate the La/Al ratio in each sample. A plot of room-temperature sheet resistance as a function of the La/Al ratio. This file establishes a correlation between film stoichiometry and electronic transport at the interface. Figure 2 – Superconducting Phase Diagram under Gate Voltage This file includes resistance versus temperature measurements and phase diagrams of superconductivity for different La/Al ratios. It contains: R(T) curves measured at various gate voltages between 0.03 K and 0.4 K. Color plots of normalized resistance as a function of temperature and gate voltage. The extracted critical temperature.Tc as a function of carrier density, and its evolution with stoichiometry. These data define the superconducting phase space and illustrate how stoichiometric control enhances superconductivity. Figure 3 – Atomic-Scale Chemical Mapping via STEM-EELS This file contains data from Scanning Transmission Electron Microscopy (STEM) combined with Electron Energy Loss Spectroscopy (EELS). It includes: High-resolution HAADF-STEM images of the LAO/STO interface. Elemental maps of La and Al across the interface for four different samples. Layer-by-layer profiles of the La/Al ratio, compared to the average ratios obtained from XPS. The data show cation intermixing, La enrichment at specific layers, and allow direct visualization of stoichiometric gradients at the atomic scale. Figure 4 – Gate-Dependent Hall Carrier Density This file includes Hall effect measurements R_H (B) at different gate voltages. It provides: Hall resistance curves as a function of magnetic field in the low- and high-doping regimes. Carrier densities extracted from linear fits at low field and two-band fits at high field. Identification of the Lifshitz transition, marked by the occupation of a second conduction band (dxz/yz). The dataset illustrates the evolution from single-band to two-band transport and quantifies carrier densities across this transition. Figure 5 – Carrier Density, Mobility, and Mean Free Path in t₂g Subbands This file presents data extracted from two-band model fits of the Hall effect. It includes: Carrier densities for dxy and dxz/yz subbands as a function of gate voltage. Corresponding mobilities for each subband, revealing the high-quality transport regime. Estimates of mean free path compared with the superconducting coherence length. These results demonstrate that high mobility can be achieved in both bands and that the system reaches the clean limit required for unconventional superconductivity.
description: Dataset Description: Stoichiometric Control of Electron Mobility and 2D Superconductivity at LaAlO₃/SrTiO₃ Interfaces The dataset associated with the study "Stoichiometric Control of Electron Mobility and 2D Superconductivity at LaAlO₃/SrTiO₃ Interfaces" addresses a central question in the field of complex oxide interfaces: how precise control of cation stoichiometry in LaAlO₃ thin films affects the electronic properties and superconducting behavior of the two-dimensional electron system (2DES) that emerges at the interface with SrTiO₃. Motivation Interfacial superconductivity at oxide heterostructures such as LaAlO₃/SrTiO₃ (LAO/STO) is a model system to explore emergent quantum phases. However, the interplay between stoichiometry, defect chemistry, and electronic transport remains poorly understood. This work aims to systematically quantify how deviations in La/Al ratio—controlled via laser fluence in pulsed laser deposition—modify electron mobility, carrier density, and superconductivity at the interface. The ability to reproducibly engineer high-mobility interfaces in the clean limit is crucial for future oxide electronics and quantum device applications. Dataset Content and Structure The dataset includes the following categories of data: X-ray Photoelectron Spectroscopy (XPS) – Measurements of the La/Al cation ratio for a series of LAO films grown under different laser energy densities. Transport Measurements – Sheet resistance, Hall effect, and superconducting transition temperatures as a function of stoichiometry and back-gate voltage. STEM-EELS Data – High-resolution scanning transmission electron microscopy images and corresponding elemental maps (La, Al, Ti, O) at the LAO/STO interface. Superconducting Phase Diagrams – Gate-tunable superconducting properties plotted against carrier density and mobility. Band Structure Models – Tight-binding calculations and band-filling analysis used to interpret the transport data near the Lifshitz transition.
description: Figure 1. ig. 1: Schematic of the band structure and estimation of La/Al ratio using XPS. Figure 2. Superconducting phase diagram. Figure 3. Estimation of La/Al ratio using STEM-EELS. Figure 4. Gate voltage-dependent Hall carrier density. Figure 5. Estimation of carrier density and mobility in each t2g band.