Metal/ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>SrTiO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math> two-dimensional electron gases for spin-to-charge conversion

SrTiO$_3$-based two-dimensional electron gases (2DEGs) can be formed through the deposition of epitaxial oxides like LaAlO$_3$ or reactive metals such as Al. Such 2DEGs possess a finite Rashba spin-orbit coupling that has recently been harnessed to interconvert charge and spin currents direct inverse Edelstein Hall effects. Here we compare formation properties generated in SrTiO$_3$ by growth Al, Ta Y ultrathin films magnetron sputtering. By combining situ ex X-ray photoelectron spectroscopy (XPS) gain insight into reduction appearance Ti$^{3+}$ states associated with 2DEG formation, its reoxidation exposure air, transformation metal binary oxides. We extract carrier densities magnetotransport them XPS data. Finally, working samples covered an extra layer NiFe, perform spin-pumping ferromagnetic resonance experiments investigate spin-charge conversion function gate voltage. identify trends data across different sample systems discuss density transparency oxide tunnel barrier.