Polarity-tunable magnetic tunnel junctions based on ferromagnetism at oxide heterointerfaces.
Complex oxide systems have attracted considerable attention because of their fascinating properties, including the magnetic ordering at the conducting interface between two band insulators, such as LaAlO3 and SrTiO3. However, the manipulation of the spin degree of freedom at the LaAlO3/SrTiO3 heterointerface has remained elusive. Here, we have fabricated hybrid magnetic tunnel junctions consisting of Co and LaAlO3/SrTiO3 ferromagnets with the insertion of a Ti layer in between, which clearly exhibit magnetic switching and the tunnelling magnetoresistance effect below 10 K. The magnitude and sign of the tunnelling magnetoresistance are strongly dependent on the direction of the rotational magnetic field parallel to the LaAlO3/SrTiO3 plane, which is attributed to a strong Rashba-type spin-orbit coupling in the LaAlO3/SrTiO3 heterostructure. Our study provides a further support for the existence of the macroscopic ferromagnetism at LaAlO3/SrTiO3 heterointerfaces and opens a novel route to realize interfacial spintronics devices.
Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.|Department of Nanoscience, Korea University of Science and Technology, Daejeon 305-350, Korea.
Thach D N
TDN
Ngo
Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.|Department of Applied Physics, Korea University Sejong Campus, Sejong 339-700, Korea.
Jung-Won
JW
Chang
Department of Physics, Sogang University, Seoul 121-742, Korea.
Kyujoon
K
Lee
Department of Physics, Korea University, Seoul 136-713, Korea.
Seungju
S
Han
Department of Applied Physics, Korea University Sejong Campus, Sejong 339-700, Korea.
Joon Sung
JS
Lee
Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
Young Heon
YH
Kim
Department of Physics, Sogang University, Seoul 121-742, Korea.
Myung-Hwa
MH
Jung
Department of Applied Physics, Korea University Sejong Campus, Sejong 339-700, Korea.
Yong-Joo
YJ
Doh
Department of Physics, Korea University, Seoul 136-713, Korea.
Mahn-Soo
http://orcid.org/0000-0001-6901-5233
MS
Choi
Department of Physics, Chungnam National University, Daejeon 305-764, Korea.
Jonghyun
J
Song
Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
Jinhee
J
Kim