Emerging Three-Terminal Magnetic Memory Devices

Seo Won Lee, Kyoung Jin Lee

Research output: Contribution to journalReview articlepeer-review

111 Citations (Scopus)


Spin-transfer torques can switch magnetizations via a current passing through a magnetic tunnel junction, an effect that is being pursued as the switching mechanism in spin-transfer torque magnetic random access memory. Three-terminal devices are also possible. One mechanism is to have a free layer that contains a domain wall that can be manipulated by spin-transfer torques and moved between two configurations that can be read by a separate connection. An alternate approach uses the recent development of spin-orbit torques, which offer an efficient way of manipulating the magnetization of a tunnel junction by current passing through an adjacent layer. These torques allow for the separation of reading and writing currents through three-terminal devices structures. This paper presents the basic principles of spin-orbit torques, the distinguishing features of spin-orbit-torque-induced magnetization dynamics as compared to magnetization dynamics driven by conventional spin-transfer torques. From the application point of view, it presents the pros and cons of spin-orbit-torque-based three-terminal devices including magnetic random access memories. Then, it discusses domain-wall-based three-terminal devices and the advantages and disadvantages of each.

Original languageEnglish
Pages (from-to)1831-1843
Number of pages13
JournalProceedings of the IEEE
Issue number10
Publication statusPublished - 2016 Oct

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) under Grant 2015M3D1A1070465.

Publisher Copyright:
© 1963-2012 IEEE.


  • Domain-wall devices
  • magnetic random access memories
  • spin-orbit torques
  • spin-transfer torques

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Science(all)


Dive into the research topics of 'Emerging Three-Terminal Magnetic Memory Devices'. Together they form a unique fingerprint.

Cite this