04-04-2012, 04:11 PM
Spintronics Technology
[attachment=19480]
INTRODUCTION
Conventional electronic devices rely on the transport of electrical charge carriers –electrons in a semiconductor such as silicon. Now, however, physicists are trying to exploit the ‗spin‘ of 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.
BASIC PRINCIPLE
The basic principle involved is the usage of spin of the electron in addition to mass and charge of electron. Electrons like all fundamental particles have a property called spin which can be orientated in one direction or the other – called ‗spin-up‘ or ‗spin-down‘ –like a top spinning anticlockwise or clockwise. Spin is the root cause of magnetism and is a kind of intrinsic angular momentum that a particle cannot gain or lose.
Fundamentals of spin:
1. In addition to their mass, electrons have an intrinsic quantity of angular momentum
called spin, almost of if they were tiny spinning balls.
2. Associated with the spin is magnetic field like that of a tiny bar magnet lined up with
the spin axis.
Giant Magnetoresistance
Electrons like all fundamental particles have a property called spin which can be orientated in one direction or the other – called „spin-up‟ or „spin-down‟ – like a top spinning anticlockwise or clockwise. When electron spins are aligned (i.e. all spin-up or all spin-down) they create a large-scale net magnetic moment as seen in magnetic materials like iron and cobalt. Magnetism is an intrinsic physical property associated with the spins of electrons in a material.
Memory Chips
Physicists have been quick to see the further possibilities of spin valves. Not
only are they highly sensitive magnetic sensors (see Box), they can also be made to act
as switches by flipping the magnetisation in one of the layers. This allows information to
be stored as 0s and 1s (magnetisations of the layers parallel or antiparallel) as in a
conventional transistor memory device. An obvious application is a magnetic version of a
random access memory (RAM) device of the kind used in your computer. The advantage
of magnetic random access memory (MRAM) is that it is „non-volatile‟ – information isn‟t
lost when the system is switched off.
CONCLUSION
Spintronics is one of the most exciting and challenging areas in nanotechnology, important to both
fundamental scientific research and industrial applications. These spintronic-devices, combining the advantages of magnetic materials and semiconductors, are expected to be non-volatile, versatile, fast and capable of simultaneous data storage and processing, while at the same time consuming less energy. They are playing an increasingly significant role in highdensity
data storage, microelectronics, sensors, quantum computing and bio-medical applications, etc.
It is expected that the impact of spintronics to the microelectronics industry might be comparable to the development of the transistor 50 years ago.
[attachment=19480]
INTRODUCTION
Conventional electronic devices rely on the transport of electrical charge carriers –electrons in a semiconductor such as silicon. Now, however, physicists are trying to exploit the ‗spin‘ of 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.
BASIC PRINCIPLE
The basic principle involved is the usage of spin of the electron in addition to mass and charge of electron. Electrons like all fundamental particles have a property called spin which can be orientated in one direction or the other – called ‗spin-up‘ or ‗spin-down‘ –like a top spinning anticlockwise or clockwise. Spin is the root cause of magnetism and is a kind of intrinsic angular momentum that a particle cannot gain or lose.
Fundamentals of spin:
1. In addition to their mass, electrons have an intrinsic quantity of angular momentum
called spin, almost of if they were tiny spinning balls.
2. Associated with the spin is magnetic field like that of a tiny bar magnet lined up with
the spin axis.
Giant Magnetoresistance
Electrons like all fundamental particles have a property called spin which can be orientated in one direction or the other – called „spin-up‟ or „spin-down‟ – like a top spinning anticlockwise or clockwise. When electron spins are aligned (i.e. all spin-up or all spin-down) they create a large-scale net magnetic moment as seen in magnetic materials like iron and cobalt. Magnetism is an intrinsic physical property associated with the spins of electrons in a material.
Memory Chips
Physicists have been quick to see the further possibilities of spin valves. Not
only are they highly sensitive magnetic sensors (see Box), they can also be made to act
as switches by flipping the magnetisation in one of the layers. This allows information to
be stored as 0s and 1s (magnetisations of the layers parallel or antiparallel) as in a
conventional transistor memory device. An obvious application is a magnetic version of a
random access memory (RAM) device of the kind used in your computer. The advantage
of magnetic random access memory (MRAM) is that it is „non-volatile‟ – information isn‟t
lost when the system is switched off.
CONCLUSION
Spintronics is one of the most exciting and challenging areas in nanotechnology, important to both
fundamental scientific research and industrial applications. These spintronic-devices, combining the advantages of magnetic materials and semiconductors, are expected to be non-volatile, versatile, fast and capable of simultaneous data storage and processing, while at the same time consuming less energy. They are playing an increasingly significant role in highdensity
data storage, microelectronics, sensors, quantum computing and bio-medical applications, etc.
It is expected that the impact of spintronics to the microelectronics industry might be comparable to the development of the transistor 50 years ago.