### Abstract

We present a novel memory device that consists of a thin ferromagnetic layer of Fe deposited on topological insulator thin film, (Formula presented.). The ferromagnetic layer has perpendicular anisotropy, due to MgO deposited on its top surface. When current is passed on the surface of (Formula presented.), the surface of the (Formula presented.) becomes spin polarized and strong exchange interaction occurs between the d electrons in the ferromagnet and the electrons conducting the current on the surface of the (Formula presented.). Part of the current is also shunted through the ferromagnet, which generates spin transfer torque in the ferromagnet. The exchange interaction torque along with voltage-controlled magnetic anisotropy allows ultralow-energy switching of the ferromagnet. We perform micromagnetic simulations and predict switching time of the order of 2.5 ns and switching energy of the order of 0.88fJ for a ferromagnetic bit with thermal stability of (Formula presented.). Such ultralow-energy and high-speed switching of a perpendicular anisotropy ferromagnet on a topological insulator could be utilized for energy-efficient memory design.

Original language | English (US) |
---|---|

Pages (from-to) | 1-7 |

Number of pages | 7 |

Journal | Journal of Computational Electronics |

DOIs | |

State | Accepted/In press - Jan 9 2017 |

### Fingerprint

### Keywords

- Exchange interaction
- Micromagnetic simulation
- Spin transfer torque (STT )
- Topological insulator (TI )
- Voltage-controlled magnetic anisotropy (VCMA )

### ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Modeling and Simulation
- Electrical and Electronic Engineering

### Cite this

*Journal of Computational Electronics*, 1-7. DOI: 10.1007/s10825-016-0951-x

**A simulation study of voltage-assisted low-energy switching of a perpendicular anisotropy ferromagnet on a topological insulator.** / Ghosh, Bahniman; Dey, Rik; Register, Leonard F.; Banerjee, Sanjay K.

Research output: Contribution to journal › Article

*Journal of Computational Electronics*, pp. 1-7. DOI: 10.1007/s10825-016-0951-x

}

TY - JOUR

T1 - A simulation study of voltage-assisted low-energy switching of a perpendicular anisotropy ferromagnet on a topological insulator

AU - Ghosh,Bahniman

AU - Dey,Rik

AU - Register,Leonard F.

AU - Banerjee,Sanjay K.

PY - 2017/1/9

Y1 - 2017/1/9

N2 - We present a novel memory device that consists of a thin ferromagnetic layer of Fe deposited on topological insulator thin film, (Formula presented.). The ferromagnetic layer has perpendicular anisotropy, due to MgO deposited on its top surface. When current is passed on the surface of (Formula presented.), the surface of the (Formula presented.) becomes spin polarized and strong exchange interaction occurs between the d electrons in the ferromagnet and the electrons conducting the current on the surface of the (Formula presented.). Part of the current is also shunted through the ferromagnet, which generates spin transfer torque in the ferromagnet. The exchange interaction torque along with voltage-controlled magnetic anisotropy allows ultralow-energy switching of the ferromagnet. We perform micromagnetic simulations and predict switching time of the order of 2.5 ns and switching energy of the order of 0.88fJ for a ferromagnetic bit with thermal stability of (Formula presented.). Such ultralow-energy and high-speed switching of a perpendicular anisotropy ferromagnet on a topological insulator could be utilized for energy-efficient memory design.

AB - We present a novel memory device that consists of a thin ferromagnetic layer of Fe deposited on topological insulator thin film, (Formula presented.). The ferromagnetic layer has perpendicular anisotropy, due to MgO deposited on its top surface. When current is passed on the surface of (Formula presented.), the surface of the (Formula presented.) becomes spin polarized and strong exchange interaction occurs between the d electrons in the ferromagnet and the electrons conducting the current on the surface of the (Formula presented.). Part of the current is also shunted through the ferromagnet, which generates spin transfer torque in the ferromagnet. The exchange interaction torque along with voltage-controlled magnetic anisotropy allows ultralow-energy switching of the ferromagnet. We perform micromagnetic simulations and predict switching time of the order of 2.5 ns and switching energy of the order of 0.88fJ for a ferromagnetic bit with thermal stability of (Formula presented.). Such ultralow-energy and high-speed switching of a perpendicular anisotropy ferromagnet on a topological insulator could be utilized for energy-efficient memory design.

KW - Exchange interaction

KW - Micromagnetic simulation

KW - Spin transfer torque (STT )

KW - Topological insulator (TI )

KW - Voltage-controlled magnetic anisotropy (VCMA )

UR - http://www.scopus.com/inward/record.url?scp=85008698735&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85008698735&partnerID=8YFLogxK

U2 - 10.1007/s10825-016-0951-x

DO - 10.1007/s10825-016-0951-x

M3 - Article

SP - 1

EP - 7

JO - Journal of Computational Electronics

T2 - Journal of Computational Electronics

JF - Journal of Computational Electronics

SN - 1569-8025

ER -