Govt. College Of Engineering,Kalahandi
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SPINTRONICS
Alok Kumar Pradhan
Electrical Engineering
Regd. No:-1601110092
Guided by:- Asst. Prof. Bikash Meher
CONTENT
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INTRODUCTION
ALTERNATIVES OF ELECTRONICS
SPINTRONICS
THE SPIN
THE GIANT MAGNETO RESISTANCE(GMR)
SPIN VALVE
STRUCTURE AND WORKING OF GMR
MAGNETO RESISTIVE RAM(MRAM)
QUANTUM COMPUTING
ADVANTAGES OF SPINTRONICS
CONCLUSION
REFERENCE
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INTRODUCTION
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LIMITATION OF ELECTRONICS:-
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MOORE’S LAW (co. founder of INTEL)
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DATA TRANSFER ONLY BASED ON ‘𝒆− ’
(GRAPH ON MOORE’S LAW)
ALTERNATIVES OF ELECTRONICS
BIO-ELECTRONICS
POLYMER-ELECTRONICS
MOLECULAR ELECTRONICS
SPINTRONICS
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SPINTRONICS
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The conventional electronics devices ignore the spin property and rely strictly on
the transport of electrical charge electron.
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Now, however, physicists are trying to explore other property of electron ‘spin’ if
the electron rather than its charge to create a remarkable new generation of
spintronic devices which will be smaller, more versatile and more robust than those
currently making up silicon chips and circuit elements.
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It creates novel materials and devices whose properties are influenced by spin
polarised current.
THE SPIN
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The spin is represented by a vector. For an electron spinning
around the nucleus, the vector points “up” and it points
“down” for the opposite spin.
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In an ordinary electronic circuit, the spins are oriented at
random and have no effect on the current flow.
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Spintronic devices create spin-polarized currents and use the
spin to control the current flow.
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The Giant Magneto Resistance (GMR)
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Giant refers to giant change in resistance due to current.
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It is a quantum mechanical magnetoresistance effect observed in multilayers composed of
alternating ferromagnetic and non-magnetic conductive layers.
:- Discovered by Peter Grünberg and Albert Fert in 1988.
:- Nobel Prize in Physics awarded to Grünberg and Albert Fert in 2007
THE HARD DRIVE
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SPIN VALVE
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Simplest and most successful spintronic device.
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Used in HDD to read information in the form of small magnetic fields above the disk surface.
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THE STRUCTURE AND WORKING OF GMR
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A Giant Magnetoresistive device is made of at least two ferromagnetic layers separated by a
spacer layer.
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When the magnetization of the two outside layers is aligned, the resistance is at its lowest.
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Conversely when magnetization vectors are antiparallel, a high resistance is developed.
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Small fields can produce big effects. Parallel and perpendicular currents are developed
depending on the spin.
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It is also a way to control the electrical resistance at the nano scale using magnetic field.
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Magneto Resistive RAM (MRAM)
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An important spintronic device, which is supposed
Ferro magnetic layer
to be one of the first spintronic devices that have
been invented, is MRAM.
Ferro magnetic layer
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Unlike conventional random-access, MRAMs do
not lose stored information once the power is
turned off. So it is non-volatile in nature.
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mtj
Quantum Computing
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entanglement
A quantum computer is a
machine that performs
calculations based on the
laws of quantum
mechanics, which is the
behavior of particles at
the sub-atomic level.
A physical
implementation of
a qubit could use
the two energy
levels of an atom.
An excited state
representing
‘1’and a ground
state representing
‘0’.
A bit of data is
represented by a
single atom that is
in one of two
states denoted by
‘0’ and ‘1’ A single
bit of this form is
known as a qubit.
Advantages of Spintronics
Low power consumption.
Less heat dissipation.
Takes up lesser space on chip, thus more compact.
Spin manipulation is faster.
Spintronics does not require unique and specialized semiconductors.
Common metals such as Cu, Fe, Al, etc. can be used.
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Conclusion
Interest in spintronics arises, in part, from
the looming problem of exhausting the
fundamental physical limits of conventional
electronics.
However, complete reconstruction of
industry is unlikely and spintronics is a
variation of current technology.
The spin of the electron has attracted
renewed interest because it promises a wide
variety of new devices that combine logic,
storage and sensor applications.
Moreover, these "spintronic" devices might
lead to quantum computers and quantum
communication based on electronic solidstate devices, thus changing the perspective
of information technology in the 21st century.
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REFERENCE
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A. Chiolerio, Spintronic Devices. Ph.D. thesis, POLITECHNIC OF TURIN,
February 2009.
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A. M.-A. Jaroslav Fabian, “Semiconductor spintronics,” Department
of Physics, State University of New York at Buffalo, Buffalo NY, 14260,
USA, 2003.
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M. E. Flatte, “Spintronics,” IEEE TRANSACTIONS ON MAGNETICS, vol.
54, pp. 907-920, May 2007.
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R. Duine, “Spintronics, ”Leuvenlaan 4, 3584 CE Utrecht, Netherlands,
February 2010.
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The electron is not as simple as it looks.
THANK YOU.