TY - JOUR
T1 - Recent progress in the voltage-controlled magnetic anisotropy effect and the challenges faced in developing voltage-torque MRAM
AU - Nozaki, Takayuki
AU - Yamamoto, Tatsuya
AU - Miwa, Shinji
AU - Tsujikawa, Masahito
AU - Shirai, Masafumi
AU - Yuasa, Shinji
AU - Suzuki, Yoshishige
N1 - Funding Information:
Acknowledgments: This work was supported by the ImPACT Program of the Council for Science. We thank Y. Shiota, A. Kozioł-Rachwał, W. Skowroński, X. Xu, T. Ikeura, T. Ohkubo, T. Tsukahara, M. Suzuki, S. Tamaru, H. Kubota, A. Fukushima, K. Hono, K. Nakamura, T. Oda, R. Matsumoto, H. Imamura, Y. Miura, T. Taniguchi, T. Yorozu, Y. Kotani, T. Nakamura and M. Sahashi for fruitful discussions. The XAS and XMCD measurements were performed in SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (Proposal Nos. 2016B1017).
Publisher Copyright:
© 2019 by the authors.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - The electron spin degree of freedom can provide the functionality of "nonvolatility" in electronic devices. For example, magnetoresistive random access memory (MRAM) is expected as an ideal nonvolatile working memory, with high speed response, high write endurance, and good compatibility with complementary metal-oxide-semiconductor (CMOS) technologies. However, a challenging technical issue is to reduce the operating power. With the present technology, an electrical current is required to control the direction and dynamics of the spin. This consumes high energy when compared with electric-field controlled devices, such as those that are used in the semiconductor industry. A novel approach to overcome this problem is to use the voltage-controlled magnetic anisotropy (VCMA) effect, which draws attention to the development of a new type of MRAM that is controlled by voltage (voltage-torque MRAM). This paper reviews recent progress in experimental demonstrations of the VCMA effect. First, we present an overview of the early experimental observations of the VCMA effect in all-solid state devices, and follow this with an introduction of the concept of the voltage-induced dynamic switching technique. Subsequently, we describe recent progress in understanding of physical origin of theVCMA effect. Finally, new materials research to realize a highly-efficient VCMA effect and the verification of reliable voltage-induced dynamic switching with a low write error rate are introduced, followed by a discussion of the technical challenges that will be encountered in the future development of voltage-torque MRAM.
AB - The electron spin degree of freedom can provide the functionality of "nonvolatility" in electronic devices. For example, magnetoresistive random access memory (MRAM) is expected as an ideal nonvolatile working memory, with high speed response, high write endurance, and good compatibility with complementary metal-oxide-semiconductor (CMOS) technologies. However, a challenging technical issue is to reduce the operating power. With the present technology, an electrical current is required to control the direction and dynamics of the spin. This consumes high energy when compared with electric-field controlled devices, such as those that are used in the semiconductor industry. A novel approach to overcome this problem is to use the voltage-controlled magnetic anisotropy (VCMA) effect, which draws attention to the development of a new type of MRAM that is controlled by voltage (voltage-torque MRAM). This paper reviews recent progress in experimental demonstrations of the VCMA effect. First, we present an overview of the early experimental observations of the VCMA effect in all-solid state devices, and follow this with an introduction of the concept of the voltage-induced dynamic switching technique. Subsequently, we describe recent progress in understanding of physical origin of theVCMA effect. Finally, new materials research to realize a highly-efficient VCMA effect and the verification of reliable voltage-induced dynamic switching with a low write error rate are introduced, followed by a discussion of the technical challenges that will be encountered in the future development of voltage-torque MRAM.
KW - Magnetic tunnel junction
KW - Magnetoresistive random access memory
KW - Voltage-controlled magnetic anisotropy
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U2 - 10.3390/mi10050327
DO - 10.3390/mi10050327
M3 - Review article
AN - SCOPUS:85072760715
VL - 10
JO - Micromachines
JF - Micromachines
SN - 2072-666X
IS - 5
M1 - 327
ER -