Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas

TL;DR

This paper demonstrates the fabrication of a Mn5Ge3/Ge 2DHG/Mn5Ge3 spin-valve device with observed magnetoresistance signals at low temperatures, advancing the development of CMOS-compatible spintronic devices utilizing high-mobility Ge two-dimensional hole gases.

Contribution

It reports the first successful integration of ferromagnetic Mn5Ge3 contacts with a Ge 2DHG, showing potential for efficient spin injection in CMOS-compatible spintronic devices.

Findings

Magnetoresistance observed below 13 K indicating possible spin injection

Ferromagnetic Mn5Ge3 contacts grown directly into Ge quantum well

Advancement towards CMOS-compatible spintronic device realization

Abstract

Ge two-dimensional hole gases in strained modulation-doped quantum-wells represent a promising material platform for future spintronic applications due to their excellent spin transport properties and the theoretical possibility of efficient spin manipulation. Due to the continuous development of epitaxial growth recipes extreme high hole mobilities and low effective masses can be achieved, promising an efficient spin transport. Furthermore, the Ge two-dimensional hole gas (2DHG) can be integrated in the well-established industrial complementary metal-oxide-semiconductor (CMOS) devices technology. However, efficient electrical spin injection into a Ge 2DHG - a prerequisite for the realization of spintronic devices - has not yet been demonstrated. In this work, we report the fabrication and low-temperature magnetoresistance measurements of a laterally structured Mn5Ge3/Ge 2DHG/ Mn5Ge3 device. The ferromagnetic Mn5Ge3 contacts are grown directly into the Ge quantum well by means of an interdiffusion process with a spacing of approximately 130 nm. We observe a magnetoresistance signal for temperatures below 13 K possibly arising from successful spin injection. The results represent a step forward toward the realization of CMOS compatible spintronic devices based on a 2DHG.