Spin injection and detection in MnAs/GaAs/InAs hybrid system on GaAs(111)B through lateral non-local spin valve measurement at varied temperature

Md Earul Islam,Masashi Akabori,Kazuki Hayashida

doi:10.1063/1.5126242

Md Earul Islam, Masashi Akabori + Show 1 more

Open Access

https://doi.org/10.1063/1.5126242

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Abstract

We successfully confirmed spin injection and detection in the MnAs/GaAs/InAs hybrid system on GaAs(111)B through lateral nonlocal spin valve (NLSV) measurement at 1.5 K and 77 K. Surprisingly, we found larger NLSV signals at 77 K than that at 1.5 K. This seems to be interesting behavior compared to typical temperature dependent spin injection and detection study. We studied in depth the NLSV signals to extract spin parameters such as spin diffusion length and spin injection efficiency in the hybrid system. We found spin diffusion length to be ∼10 µm and ∼7 µm at 1.5 K and 77 K, respectively, and also found spin injection efficiency to be ∼1.6% and ∼2.5% at 1.5 K and 77 K, respectively. The reason behind higher injection efficiency at 77 K comes from better impedance matching between MnAs and InAs at 77 K than that at 1.5 K due to large temperature variation of MnAs resistivity.

Highlights

Ferromagnetic (FM)/semiconductor (SC) hybrid systems are important in semiconductor spintronics to realize various spin transistors such as spin-field-effect transistor and spin metaloxide-semiconductor field-effect transistor, which are expected to have features such as nonvolatility, reconfigurable logic functions, and low power consumption
Due to the flowing of spin polarized charge current in the LSV measurement, there are possibilities to affect the intrinsic signal of interest by the drift electric field,4 anisotropic magnetoresistance (AMR),5 or local Hall effect (LHE)
In nonlocal spin valve (NLSV) measurement, such a spurious effect can be avoided7,8 because spin polarized charge current and pure spin current are separated in nonlocal arrangement

Summary

INTRODUCTION

Ferromagnetic (FM)/semiconductor (SC) hybrid systems are important in semiconductor spintronics to realize various spin transistors such as spin-field-effect transistor (spin-FET) and spin metaloxide-semiconductor field-effect transistor (spin-MOSFET), which are expected to have features such as nonvolatility, reconfigurable logic functions, and low power consumption. The spin transistors require to have ferromagnetic (FM) source and drain for spin polarized charge current injection and detection, semiconducting channel for spin-polarized charge current transport, and a gate electric field for the transport control. The evaluation about SOC of InAs is beyond the discussion of this paper To this end, we choose MnAs as a spin source for spin injection and detection in combination with III-V, which has already emerged as a promising material for future spintronic devices. The central issues of this paper are to investigate spin injection and detection in the MnAs/GaAs/InAs hybrid system on GaAs(111)B through lateral spin valve geometry at varied temperatures. We compare their behaviors in detail through NLSV measurement at varied temperature to understand in depth about spin-related parameters into the hybrid system

LATERAL SPIN VALVE STUDY

CONCLUSION