Oxide interface based quantum wires

Yoram Dagan

Oxide interfaces can have physical properties which are very different from their constituting materials. These properties can manifest themselves in various orders such as superconductivity, magnetism, and ferroelectricity. Of these interfaces probably the most studied one is the interface between the two insulating perovskites: SrTiO3 and LaAlO3, which exhibits properties of a two dimensional electron gas, superconductivity strong spin-orbit interaction and magnetism.

In this talk I will briefly review the state of the art research of oxide interfaces and especially SrTiO3/LaAlO3 interface. I will then describe our findings on nano-sized bridges (nanowires) and our new technique to fabricate quantum wires from such interfaces.

From transport in the nanowires we can probe an anomalous magnetic order consisting of domains with opposite magnetization having a higher coercive field for in-plane orientation. When making the wires even narrower a quantized conductance is observed with discrete steps as a function of gate voltage characteristics of a one dimensional channel. The step size of exactly half the quantum of conductance is an evidence for absence of spin degeneracy.

The possibility to control correlation effects, spin-orbit interactions and coupling to superconductivity makes this wire a laboratory for studying Majorana fermions and spin dependent transport