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Depositing disordered Al on top of $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ is a cheap and easy way to create a two-dimensional electron system in the $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ surface layers. To facilitate future device applications, we passivate the heterostructure by a disordered $\mathrm{La}\mathrm{Al}{\mathrm{O}}_{3}$ capping layer to study the electronic properties by complementary x-ray photoemission spectroscopy and transport measurements on the very same samples. We also tune the electronic interface properties by adjusting the oxygen pressure during film growth.

The authors study, as a promising candidate for photovoltaic applications, the Mott insulator LaVO${}_{3}$, epitaxially grown as a thin film on SrTiO${}_{3}$. They elucidate the electronic properties by electrical transport and photoemission measurements. The origin of the conducting interface is identified to be electronic reconstruction due to the polar discontinuity between film and substrate. The authors find a potential gradient in the film and a downward band bending in the substrate, with the electrons residing in interfacial Ti states.

We present room temperature memristive switching in a nano-patterned LaAlO3/SrTiO3 wire with laterally defined gates in proximity to the wire. Closed bias voltage sweeps show pinched hysteresis loops with zero bias resistance values of up to Ron = 8 MΩ and Roff = 1.2 GΩ for the on and off state, respectively. The maximum Roff/Ron ratio is 150. Frequency dependent measurements show a cutoff frequency of around 10 Hz, and the alteration of set point voltages enables us to precisely set and control the resistance off-on ratio. We explain the memristive switching by charge localization on the laterally defined gates, which couple capacitively to the wire and enhance or decrease the resistance dependent on the amount of transferred charges. Our finding enables the realization of geometry-based memristive switching devices, which make use of the form-dependent wire-gate capacitance.

We report gate-tunable memristive switching in patterned LaAlO3/SrTiO3 interfaces at cryogenic temperatures. The application of voltages in the order of a few volts to the back gate of the device allows controlling and switching-on and -off the inherent memory functionality (memristance). For large and small gate voltages a simple non-linear resistance characteristic is observed while a pinched hysteresis loop and memristive switching occurs in an intermediate voltage range. The memristance is further controlled by the density of oxygen vacancies, which is tuned by annealing the sample at 300 {\deg}C in nitrogen atmosphere. Depending on the annealing time the memristance at zero gate voltage can be switched on and off leading to normally-on and normally-off memristors. The presented device offers reversible and irreversible control of memristive characteristics by gate voltages and annealing, respectively, which may allow to compensate fabrication variabilities of memristors that complicate the realization of large memristor-based neural networks., Comment: 14 pages, 4 figures