Fractionally delta-doped oxide superlattices for higher carrier mobilities

TL;DR

This paper demonstrates that fractional delta-doping in oxide superlattices can precisely control electron filling, leading to a transition from insulator to metal and significantly improved carrier mobilities in 2D electron gas systems.

Contribution

It introduces a novel fractional delta-doping technique to tune electron filling and enhance mobility in oxide superlattices.

Findings

Realization of insulator-metal transition via fractional delta-doping.

Atomic-scale control of d-electron band filling.

Substantially enhanced carrier mobilities achieved.

Abstract

A 2D electron gas system in an oxide heterostructure serves as an important playground for novel phenomena. Here, we show that, by using fractional delta-doping to control the interface's composition in LaxSr1-xTiO3/SrTiO3 artificial oxide superlattices, the filling-controlled 2D insulator-metal transition can be realized. The atomic-scale control of d-electron band filling, which in turn contributes to the tuning of effective mass and density of the charge carriers, is found to be a fascinating route to substantially enhanced carrier mobilities.