We describe the transport properties of mesoscopic devices based on the two dimensional electron gas (2DEG) present at the LaAlO3/SrTiO3 interface. Bridges with lateral dimensions down to 500 nm were realized using electron beam lithography. Their detailed characterization shows that processing and confinement do not alter the transport parameters of the 2DEG. The devices exhibit superconducting behavior tunable by electric field effect. In the normal state, we measured universal conductance fluctuations, signature of phase-coherent transport in small structures. The achievement of reliable lateral confinement of the 2DEG opens the way to the realization of quantum electronic devices at the LaAlO3/SrTiO3 interface.

We report on the occurrence of multiple hopping and retrapping of a Brownian particle in a tilted washboard potential. The escape dynamic has been studied experimentally by measuring the switching current distributions as a function of temperature in a moderately damped NbN/MgO/NbN Josephson junction. At low temperatures the second moment of the distribution increases in agreement with calculations based on Kramers thermal activation regime. After a turnover temperature T*, the shape of the distributions starts changing and width decreases with temperature. We analyze the data through fit of the switching probability and Monte Carlo simulations and we find a good agreement with a model based on a multiple retrapping process.

We have studied the electronic properties of the 2D electron liquid present at the LaAlO₃/SrTiO₃ interface in series of samples prepared at different growth temperatures. We observe that interfaces fabricated at 650 °C exhibit the highest low temperature mobility ($\approx 10\hspace{0.17em}000\hspace{0.17em}{\text{cm}}^2\hspace{0.17em}{\mathrm{V}}^{-1}\hspace{0.17em}{\mathrm{s}}^{-1}$ ) and the lowest sheet carrier density ($\approx 5\times {10}^{12}\hspace{0.17em}{\text{cm}}^{-2}$ ). These samples show metallic behavior and Shubnikov-de Haas oscillations in their magnetoresistance. Samples grown at higher temperatures (800–900 °C) display carrier densities in the range of $\approx 2-5\times {10}^{13}\hspace{0.17em}{\text{cm}}^{-2}$ and mobilities of $\approx 1000\hspace{0.17em}{\text{cm}}^2\hspace{0.17em}{\mathrm{V}}^{-1}\hspace{0.17em}{\mathrm{s}}^{-1}$ at 4 K. Reducing their carrier density by field effect to $8\times {10}^{12}\hspace{0.17em}{\text{cm}}^{-2}$ lowers their mobilities to $\approx 50\hspace{0.17em}{\text{cm}}^2\hspace{0.17em}{\mathrm{V}}^{-1}\hspace{0.17em}{\mathrm{s}}^{-1}$ bringing the conductance to the weak-localization regime.