Spin Valves in Microelectronics (A Review)

• Published in: Semiconductors (Woodbury, N.Y.) Vol. 55; no. 13; pp. 1008 - 1020
• Main Authors: Iusipova, Iu. A., Popov, A. I.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2021; Springer; Springer Nature B.V
• Subjects: Analysis; Basic Research; Bayesian analysis; Biosensors; Boolean; Boolean algebra; Disk drives; Electromagnetism; Giant magnetoresistance; Hard disks; Magnetic Materials; Magnetism; Magnetoresistivity; Microelectronics; Oscillators; Physics; Physics and Astronomy; Random access memory; Spin valves; Valves; magnetic tunnel junction; magnetoresistive random access memory; hard disc drive read heads; magnetic biosensors; spin logic; spin valve; spin transfer nano-oscillators; giant magnetoresistance
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S1063782621130108

Layered spin-valve structures are basic elements of micromagnetic devices. Small dimensions, CMOS compatibility, good scalability, and a diversity of operation conditions make spin-valve structures a universal component of modern microelectronics. The aim of this review is to analyze, systematize, and generalize the fundamentals of the operation, experimental data, and application of spin valves. Hard disk drives, magnetoresistive random access memory, spin-transfer nano-oscillators, magnetic biosensors, and various computing systems operating on the basis of stochastic and deterministic logic are reviewed. The key theoretical studies on the giant magnetoresistance and spin transport are considered. Data on different types of hard disk reading heads are systematized and their architecture and parameters are compared. It is shown how modern investigations of nanomagnetic phenomena accelerates the recording density growth. The state of research on the magnetoresistive random access memory is analyzed. The issues of energy efficiency and enhancement of the degree of integration in these devices are discussed. The latest progress in the materials, geometry, and properties of spin-transfer nano-oscillators and the problems and prospects of this technology are considered. The theoretical and experimental studies are analyzed in which the spin-valve structures perform Boolean and non-Boolean logic operations. It is demonstrated how the stochastic nature of the unstable switching of spin valves is used in nonconventional computing systems, specifically, the neuromorphic or Bayesian networks. The principles of operation of spin valves as magnetic biosensors and the advantages of their application are discussed.