A two-dimensional electron gas emerged at a LaAlO3/SrTiO3 interface is an ideal system for "spin-orbitronics" as the structure itself strongly couple the spin and orbital degree of freedom through the Rashba spin-orbit interaction. One of core experiments toward this direction is the nonlocal spin transport measurement, which has remained elusive due to the low spin injection efficiency to this system. Here we bypass the problem by generating a spin current not through the spin injection from outside but instead through the inherent spin Hall effect and demonstrate the nonlocal spin transport. The analysis on the nonlocal spin voltage, confirmed by the signature of a Larmor spin precession and its length dependence, displays that both D'yakonov-Perel' and Elliott-Yafet mechanisms involve in the spin relaxation at low temperature. Our results show that the oxide heterointerface is highly efficient in spin-charge conversion with exceptionally strong spin Hall coefficient λ ∼ 0.15 ± 0.05 and could be an outstanding platform for the study of coupled charge and spin transport phenomena and their electronic applications.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (NRF) of Korea (Nos. 2014R1A1A2055685 and 2016R1D1A1B03935019) funded by the Ministry of Education, Science, and Technology and Future Challenge Project or Creativity and Innovation Project (No. 1.140092.01) funded by the Ulsan National Institute of Science and Technology. This research was also supported by the Korea Institute of Science and Technology (Nos. 2E26370 and 2E26380). H.-W. L. was supported by the NRF of Korea (No. 2011-0030046).
© 2016 American Chemical Society.
- Nonlocal spin diffusion
- Oxide heterointerface
- Rashba spin-orbit interaction
- Spin Hall effect
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics
- Mechanical Engineering