Quantum Transport in Complex Oxides

Superconducting effects in 2D materials have been shown to host exotic states not found in higher dimensional systems. Most 2D superconductors are made from materials that are conducting in their normal state, such as Al thin films or more exotic systems like magic-angle graphene. Counterintuitively however, the interface of the insulators KTaO₃ and LaSrMnO₃ has been shown to host a superconducting electron gas with exotic properties. Work performed in the Finkelstein lab has measured the anisotropic transport properties of the superconducting state, hinting at the rich physics that could be present in this system. The kinetic inductance in this system is expected to be very extremely high due to the 2D nature whilst KTaO₃ itself has a high dielectric constant(~4000) at low temperatures. Therefore we are able to modulate the superconducting state by applying a gate voltage, despite the high carrier density (~10¹³cm^-2).These properties of high kinetic inductance and gate tunability make KTaO₃ heterostructures a promising platform for a novel, scalable superconducting qubit system.