1
|
Su Y, Zhang J, Hong J, You L. The effect of insertion layer on the perpendicular magnetic anisotropy and its electric-field-induced change at Fe/MgO interface: a first-principles investigation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:454001. [PMID: 32679571 DOI: 10.1088/1361-648x/aba721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
The development of ultralow power and high density nonvolatile magnetic random access memory stimulates the search for promising materials in magnetic tunnel junction with large voltage-controlled magnetic anisotropy (VCMA) efficiency. In this work, we investigate the 4dand 5dtransition metal interlayer effect on perpendicular magnetic anisotropy (PMA) and VCMA at Fe/MgO interface by using first-principles calculations. Large PMA more than 11 mJ m-2is found at Fe/MgO interface with Pt insertion layer and the mechanism for PMA is clarified based on the second order perturbation theory. Furthermore, we find that the magnitude and the sign of VCMA efficiency are varied by introducing different insertions at Fe/MgO interface. The Re and Os interlayers lead to a sizable increase in both of the PMA and the VCMA coefficient. Our findings may further emphasize the essential importance of the interface structure on PMA and VCMA and may offer new material platforms for low-power consumption spintronic devices.
Collapse
Affiliation(s)
- Yurong Su
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074 Wuhan, People's Republic of China
| | - Jia Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, People's Republic of China
| | - Jeongmin Hong
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074 Wuhan, People's Republic of China
| | - Long You
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074 Wuhan, People's Republic of China
| |
Collapse
|
2
|
Ligand-induced activation of ERK1/2 signaling by constitutively active G s-coupled 5-HT receptors. Acta Pharmacol Sin 2019; 40:1157-1167. [PMID: 30833707 DOI: 10.1038/s41401-018-0204-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023] Open
Abstract
5-HT4R, 5-HT6R, and 5-HT7AR are three constitutively active Gs-coupled 5-HT receptors that have key roles in brain development, learning, memory, cognition, and other physiological processes in the central nervous system. In addition to Gs signaling cascade mediated by these three 5-HT receptors, the ERK1/2 signaling which is dependent on cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activation downstream of Gs signaling has also been widely studied. In this study, we investigated these two signaling pathways originating from the three Gs-coupled 5-HT receptors in AD293 cells. We found that the phosphorylation and activation of ERK1/2 are ligand-induced, in contrast to the constitutively active Gs signaling. This indicates that Gs signaling alone is not sufficient for ERK1/2 activation in these three 5-HT receptors. In addition to Gs, we found that β-arrestin and Fyn are essential for the activation of ERK1/2. Together, these results put forth a novel mechanism for ERK1/2 activation involving the cooperative action of Gs, β-arrestin, and Fyn.
Collapse
|
3
|
Nozaki T, Yamamoto T, Miwa S, Tsujikawa M, Shirai M, Yuasa S, Suzuki Y. Recent Progress in the Voltage-Controlled Magnetic Anisotropy Effect and the Challenges Faced in Developing Voltage-Torque MRAM. MICROMACHINES 2019; 10:E327. [PMID: 31096668 PMCID: PMC6562605 DOI: 10.3390/mi10050327] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/10/2019] [Accepted: 05/12/2019] [Indexed: 12/04/2022]
Abstract
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 the VCMA 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.
Collapse
Affiliation(s)
- Takayuki Nozaki
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki 305-8568, Japan.
| | - Tatsuya Yamamoto
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki 305-8568, Japan.
| | - Shinji Miwa
- The Institute of Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8531, Japan.
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Masahito Tsujikawa
- Research Institute of Electrical Communication, Tohoku University, Sendai, Miyagi 980-8577, Japan.
| | - Masafumi Shirai
- Research Institute of Electrical Communication, Tohoku University, Sendai, Miyagi 980-8577, Japan.
| | - Shinji Yuasa
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki 305-8568, Japan.
| | - Yoshishige Suzuki
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki 305-8568, Japan.
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| |
Collapse
|