Lateral Size Confinement Effect on Charge Transport at the Interface of LaAlO₃/SrTiO₃

As shown in some earlier works, an additional lateral charge confinement of 2-dimensional electron liquid (2DEL) at the interface of LaAlO₃/SrTiO₃ (LAO/STO) has revealed several intriguing phenomena, such as exotic electron pairing outside of the superconducting regime and a mysterious boost in electron mobility. In this study, we have grown ten unit cells of epitaxial LAO films on the TiO₂-terminated STO substrates by the oxide molecular beam epitaxy (MBE) technique. We also developed a feasible fabrication procedure to define the macroscopic 2DEL at the LAO/STO interface into micro-meter sized Hall-bar patterns with different line widths. The sheet resistances were found to be inversely proportional to the line widths as expected, where the sheet carrier density could be largely tuned by applying gate voltage via a bottom gate. The influence of additional lateral size confinement on magneto-transport properties of the 2DEL will be presented and discussed.