Electrical spin injection in modulation-doped GaAs from an in situ grown Fe/MgO layer

Seong Hoon Shim, Hyung Jun Kim, Hyun Cheol Koo, Yun-Hi Lee, Joonyeon Chang

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Abstract

We study spin accumulation in n-doped GaAs that were electrically injected from Fe via MgO using three-terminal Hanle measurement. The Fe/MgO/GaAs structures were prepared in a cluster molecular beam epitaxy that did not require the breaking of the vacuum. We found the crystal orientation relationship of epitaxial structures Fe[100]//MgO[110]//GaAs[110] without evident defects at the interface. Control of depletion width and interface resistance by means of modulation doping improves spin injection, leading to enhanced spin voltage (ΔV) of 6.3-mV at 10-K and 0.8-mV even at 400-K. The extracted spin lifetime and spin diffusion length of GaAs are 220 ps and 0.77-μm, respectively, at 200-K. MgO tunnel barrier grown in situ with modulation doping at the interface appears to be promising for spin injection into GaAs.

Original languageEnglish
Article number102407
JournalApplied Physics Letters
Volume107
Issue number10
DOIs
Publication statusPublished - 2015 Sep 7

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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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