Universal Conductance Fluctuations in Electrolyte-Gated SrTiO3 Nanostructures

We report low-temperature magnetoconductance measurements of a patterned two-dimensional electron system at the surface of strontium titanate, gated by an ionic liquid electrolyte. We observe universal conductance fluctuations, a signature of phase-coherent transport in mesoscopic devices. From the universal conductance fluctuations, we extract an electron dephasing rate linear in temperature, characteristic of electron-electron interaction in a disordered conductor. The dephasing rate has a temperature-independent offset, which could possibly be explained by the presence of unscreened local magnetic moments in the sample.