10.10 Conclusions
265
of GMR effect in Magnetic Data storage, internal structure of a magnetic hard disk,
operation of Magnetoresistance Read Heads and finally the evolution of magnetoresistance read head sensor with the implementation of GMR sensor. We have also
carried out discussion on spin valve sensors and some important features of spin-valve
GMR read head applications. A detailed discussion on Magnetic Random Access
Memories (MRAM) has been presented here. In this direction, we have addressed
application based on spin-tunnel junctions, its background, and ‘Why MRAM should
be used?’. We have elaborated the discussion on the basic cell operation of MTJ
based—Magnetic Random Access Memories (MRAM). Furthermore, Spin Transfer
Torque (STT)—MRAM has been described. Here, we have also addressed the issue
of perpendicular STT-MRAM, application of STT-MRAM, the latest application
of STT-MRAM, etc. We have carried out discussion on spintronics sensors that
include anisotropic magnetoresistance sensor, some GMR-based sensors applications and some magnetic tunnel junction-based TMR sensors applications. Some
very intriguing topics on Spin FET, Race Track Memory, Quantum Computing have
also been highlighted and described in this chapter.
10.11 Exercises
1. What is the typical multilayer structure used in spin-valve devices?
2. What is called synthetic antiferromagnet?
3. How to use spintronic devices for the detection of magnetic field?
4. How could the non-volatile ‘Selective bit programming’ could be achieved in
MTJ-based Magnetoresistive Random Access Memories (MRAM)?
5. Write a short note on spin valve sensor for read head.
6. Write a short note on MTJ-based Magnetoresistive Random Access Memories
(MRAM).
References
M.N. Baibich, J.M. Broto, A. Fert, et al., Giant magnetoresistance of (001)Fe/(001)Cr magnetic
super lattices. Phys. Rev. Lett. 61 2472–2475 (1988)
M. Bennati, K. Németh, P.R. Surja´ n, M. Mehring, Zero-field-splitting and
-electron spin densities
in thelowest excited triplet state of oligothiophenes. J. Chem. Phys. 105, 4441–4447 (1996)
L. Berger et al., J. Appl. Phys. 64, 5459 (1988)
G. Binasch, P. Grünberg, F. Saurenbach, W. Zinn, Enhanced magnetoresistance in layered magnetic
structures with antiferromagnetic interlayer exchange. Phys. Rev. B 39, 4828(R) – 4830 (1989)
J.H. Burroughes, D.D.C. Bradley, A.R. Brown, Light-emitting diodes based on conjugated
polymers. Nature (London) 347, 539–541(1990)
P. Chuang, S.-C. Ho, L.W. Smith et al., All-electric and all-semiconductor spin field effect transistors.
Nat. Nanotechnol. 10, 35–39 (2015)
S. Datta, How we proposed the spin transistor. Nat. Electron. 1, 604 (2018)
265
of GMR effect in Magnetic Data storage, internal structure of a magnetic hard disk,
operation of Magnetoresistance Read Heads and finally the evolution of magnetoresistance read head sensor with the implementation of GMR sensor. We have also
carried out discussion on spin valve sensors and some important features of spin-valve
GMR read head applications. A detailed discussion on Magnetic Random Access
Memories (MRAM) has been presented here. In this direction, we have addressed
application based on spin-tunnel junctions, its background, and ‘Why MRAM should
be used?’. We have elaborated the discussion on the basic cell operation of MTJ
based—Magnetic Random Access Memories (MRAM). Furthermore, Spin Transfer
Torque (STT)—MRAM has been described. Here, we have also addressed the issue
of perpendicular STT-MRAM, application of STT-MRAM, the latest application
of STT-MRAM, etc. We have carried out discussion on spintronics sensors that
include anisotropic magnetoresistance sensor, some GMR-based sensors applications and some magnetic tunnel junction-based TMR sensors applications. Some
very intriguing topics on Spin FET, Race Track Memory, Quantum Computing have
also been highlighted and described in this chapter.
10.11 Exercises
1. What is the typical multilayer structure used in spin-valve devices?
2. What is called synthetic antiferromagnet?
3. How to use spintronic devices for the detection of magnetic field?
4. How could the non-volatile ‘Selective bit programming’ could be achieved in
MTJ-based Magnetoresistive Random Access Memories (MRAM)?
5. Write a short note on spin valve sensor for read head.
6. Write a short note on MTJ-based Magnetoresistive Random Access Memories
(MRAM).
References
M.N. Baibich, J.M. Broto, A. Fert, et al., Giant magnetoresistance of (001)Fe/(001)Cr magnetic
super lattices. Phys. Rev. Lett. 61 2472–2475 (1988)
M. Bennati, K. Németh, P.R. Surja´ n, M. Mehring, Zero-field-splitting and
-electron spin densities
in thelowest excited triplet state of oligothiophenes. J. Chem. Phys. 105, 4441–4447 (1996)
L. Berger et al., J. Appl. Phys. 64, 5459 (1988)
G. Binasch, P. Grünberg, F. Saurenbach, W. Zinn, Enhanced magnetoresistance in layered magnetic
structures with antiferromagnetic interlayer exchange. Phys. Rev. B 39, 4828(R) – 4830 (1989)
J.H. Burroughes, D.D.C. Bradley, A.R. Brown, Light-emitting diodes based on conjugated
polymers. Nature (London) 347, 539–541(1990)
P. Chuang, S.-C. Ho, L.W. Smith et al., All-electric and all-semiconductor spin field effect transistors.
Nat. Nanotechnol. 10, 35–39 (2015)
S. Datta, How we proposed the spin transistor. Nat. Electron. 1, 604 (2018)