A novel technique to make Ohmic contact to a buried two-dimensional electron gas in a molecular-beam-epitaxy grown $GaAs/Al_{0.3}Ga_{0.7}As$ heterostructure with Mn $\delta$-doping

TL;DR

This paper introduces a new method for creating Ohmic contacts to a buried 2DEG in a GaAs/AlGaAs heterostructure with Mn doping, achieving high mobility and preserving magnetic properties.

Contribution

The paper presents a novel technique for making Ohmic contact to a buried 2DEG in a Mn-doped heterostructure without damaging its magnetic characteristics.

Findings

Achieved a 2DEG with high mobility (~600 cm^2/Vs) at 4.2K.

Reported the highest mobility in GaMnAs systems to date.

Developed a new contact fabrication method that preserves magnetic properties.

Abstract

We report on the growth and characterization of a new Diluted Magnetic Semiconductor (DMS) heterostructure that presents a Two-Dimensional Electron Gas (2DEG) with a carrier density $n \sim 1.08 \times 10^{12} cm^{-2}$ and a mobility $\mu \sim 600 cm^{2} / (Vs)$ at T $\sim$ 4.2K. As far as we know this is the highest mobility value reported in the literature for GaMnAs systems. A novel technique was developed to make Ohmic contact to the buried 2DEG without destroying the magnetic properties of our crystal.