TY - JOUR
T1 - Sign inversion phenomenon of voltage-induced tunnel magnetocapacitance
AU - Nakagawa, Takeru
AU - Ogata, Kentaro
AU - Nakayama, Yusuke
AU - Xiao, Gang
AU - Kaiju, Hideo
N1 - Funding Information:
This research was supported by the Grant-in-Aid for Scientific Research (B) (No.18H01485) and Challenging Exploratory Research Program (No. 19K22093) funded by the Japan Society for the Promotion of Science (JSPS), the Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials and the Cooperative Research Program of “Network Joint Research Center for Materials and Devices” funded by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), and Research Project funded by the Center for Spintronics Research Network (CSRN) at Keio and Tohoku University.
Publisher Copyright:
© 2021 Author(s).
PY - 2021/5/3
Y1 - 2021/5/3
N2 - Tunnel magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) has recently attracted interest due to unique properties, such as large magnetic response, thermal stability, and robustness to the bias voltage. In this Letter, we report the sign inversion phenomenon of TMC observed with frequency modulation and dc voltage application to MgO-based MTJs at room temperature. A negative TMC is observed in the frequency region of about kHz due to the appearance of spin capacitance. By applying a dc voltage (a few hundred mV) in this frequency region, the spin flip is promoted in the parallel configuration of MTJs. This results in the observation of the sign inversion of TMC from negative to positive. These physical pictures can be well explained by the calculation based on the modified Debye-Fröhlich model. Our research offers a deeper understanding of AC spin transports, DC spin accumulation, equilibrium and non-equilibrium spin dynamics.
AB - Tunnel magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) has recently attracted interest due to unique properties, such as large magnetic response, thermal stability, and robustness to the bias voltage. In this Letter, we report the sign inversion phenomenon of TMC observed with frequency modulation and dc voltage application to MgO-based MTJs at room temperature. A negative TMC is observed in the frequency region of about kHz due to the appearance of spin capacitance. By applying a dc voltage (a few hundred mV) in this frequency region, the spin flip is promoted in the parallel configuration of MTJs. This results in the observation of the sign inversion of TMC from negative to positive. These physical pictures can be well explained by the calculation based on the modified Debye-Fröhlich model. Our research offers a deeper understanding of AC spin transports, DC spin accumulation, equilibrium and non-equilibrium spin dynamics.
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U2 - 10.1063/5.0050304
DO - 10.1063/5.0050304
M3 - Article
AN - SCOPUS:85105275805
SN - 0003-6951
VL - 118
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 18
M1 - 182403
ER -