12-05-2011, 12:13 PM
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SPINTRONICS
(APPLICATION OF NANOTECHNOLOGY)
ABSTRACT:
“Spintronics” is an emergent NANOtechnology, which uses the spin of an electron instead of or in addition to the charge of an electron. Electron spin has two states either “up” or “down”. Aligning spins in material creates magnetism. Moreover, magnetic field affects the passage of spin-up and spin-down electrons differently the paper starts with the detail description of the fundamentals and properties of the spin of the electrons. It proceeds with a note on magnetoresistance, the development of Giant Magnetoresistance (GMR) and devices like Magneto Random Access Memory, which are the new version of the traditional RAMs. It describe how this new version of RAMs which can revolutionize the memory industry. There is also detailed explanation of the way, how this revolution can increase the data density in our memory systems. It is followed by an account of new Spin Field Effect Transistors. It also specifies the differences between electronic devices and spintronic devices. It also gives the hurdles due to the presence of holes.
This paper also discusses about a quantum computer, which uses qubits rather than normal binary digits for computations. It also gives the hurdles due to the presence of holes.
Finally it ends with a note on why we should switch on this technology. Ran road track and conveyor belts kept the Ford’s assemble line running. At that time, his method of production was lauded and was considered most efficient. But that ford’s assembly plant, which was only eulogized in his time, will look strange to those who were born and raised up in the 21st century. Because the machines in the next 50 years will get increasingly smaller – so small that thousands of machines will fit into the full stop at the end of this line. This branch of engineering which deals with things smaller than 100 nanometres is termed as NANOtechnology. Eric Dexler first coined it in his book “engine of creation”.
In this paper we will discuss about a filed of Nanotechnology, which is believed to replace conventional electronics in the near future, i.e. “spintronics”.
History of Nanotechnology:
As nanoscience has advanced and discoveries in the field applied, the potential contributions of nanotechnology to future economic growth has brought increasing government attention. Today, nanotechnology is a top research priority of the Bush administration.
Attempts to coordinate federal work on the nanoscale began in November 1996, when staff members from several agencies decided to meet regularly to discuss their plans and programs in nanoscale science and technology. This group continued informally until September 1998, when it was designated as the Interagency Working Group on Nanotechnology (IWGN) under the National Science and Technology Council (NSTC).
The IWGN sponsored numerous workshops and studies to define the state of the art in nanoscale science and technology and to forecast possible future developments. Two relevant background publications were produced by the group between July and September 1999: Nanostructure Science and Technology: A Worldwide Study, a report based on the findings of an expert panel that visited nanoscale science and technology laboratories around the world; and Nanotechnology Research Directions, a workshop report with input from academic, private sector, and government participants. These documents laid the groundwork and provided the justification for seeking to raise nanoscale science and technology to the level of a national initiative.
In August 1999, IGWN completed its first draft of a plan for an initiative in nanoscale science and technology. The plan went through an approval process involving the President's Council of Advisors on Science and Technology (PCAST) and the Office of Science and Technology Policy . Subsequently, in its 2001 budget submission to Congress, the Clinton administration raised nanoscale science and technology to the level of a federal initiative, officially referring to it as the National Nanotechnology Initiative (NNI).
The National Nanotechnology Coordination Office (NNCO) was established to serve as the secretariat for the NSET, providing day-to-day technical and administrative support. The NNCO supports the NSET in multiagency planning and the preparation of budgets and program assessment documents. It also assists the NSET with the collection and dissemination of information on industry, state, and international nanoscale science and technology research, development, and commercialization activities. The importance of a coordinated Federal program for nanotechnology R&D was given greater recognition in 2003 with the enactment of the 21st Century Nanotechnology Research and Development Act (Public Law 108-153).
A common thread between store age, medical, industrial & molecular
Nanotechnology is an exponential curve.
The goal of early nanotechnology is to produce the first nano-sized robot arm capable of manipulating atoms and molecules into a useful producer copies of itself. Nano assembler working atom by atom would be rather slow because most desirable products are made of billions & trillions of atoms. However, an assembler robotarm could make copies of itself and those copies make copies. Then we have trillions of assemblers controlled by nano-super computers working in parallel assembling objects quickly.
What is Nanotechnology ???
Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale.
At the nanoscale, the physical, chemical, and biological properties of materials differ in fundamental and valuable ways from the properties of individual atoms and molecules or bulk matter. Nanotechnology R&D is directed toward understanding and creating improved materials, devices, and systems that exploit these new properties.
One area of nanotechnology R&D is medicine. Medical researchers work at the micro- and nano-scales to develop new drug delivery methods, therapeutics and pharmaceuticals. For a bit of perspective, the diameter of DNA, our genetic material, is in the 2.5 nanometer range, while red blood cells are approximately 2.5 micrometers. Additional information about nanoscale research in medicine is available from the National Institutes of Health. A nanometer is one-billionth of a meter; a sheet of paper is about 100,000 nanometers thick. See The Scale of Things for a comparative view of the sizes of commonly known items and nanoscale particles.
SPINTRONICS:
Imagine a data storage device of the size of an atom working at a speed of light. Imagine a microprocessor whose circuits could be changed on the fly. One minute is could be optimized for data base access. The next for transaction processing and the next for scientific number crunching. Finally, imagine a computer memory thousands of times denser and faster than today’s memories.
The above-mentioned things can be made possible with the help of an exploding science – “spintronics”.
Spintronics is a NANO technology which deals with spin dependent properties of an electron instead of or in addition to its charge dependent properties,.
Conventional electronics devices rely on the transport of electric charge carries-electrons. But there is other dimensions of an electron other than its charge and mass i.e. spin. This dimension can be exploited to create a remarkable generation of spintronic devices. It is believed that in the near future spintronics could be more revolutionary than any other thing that nanotechnology has stirred up so far.
WHY IS IT GOING TO BE ONE OF THE RAPIDLY EMERGING FIELDS?
As there is rapid progress in the miniaturization of semiconductor electronic devices leads to a chip features smaller than 100 nanometers in size, device engineers and physists are inevitable faced with a looming presence of a quantum property of an electron known as spin, which is closely related to magnetism. Devices that rely on an electron spin to perform their functions from the foundations of spintronics.
Information-processing technology has thus far relied on purely charge based devices ranging from the now quantum, vaccum tube today’s million transistor microchips. Those conventional electronic devices move electronic charges around, ignoring the spin that tags along that side on each electron.
ELECTRON SPIN:
FUNDAMENTALS OF SPIN
1. In addition to their mass and electric charge, 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.
3. Scientists represent the spin with a vector. For a sphere spinning “west to east”, the vector points “north” or “up”. It points “down” for the opposite spin.
4. In a magnetic field, electrons with “spin up” and “spin down” have different energies.
5. In an ordinary electronic circuit the spins are oriented at random and have no effect on current flow.
6. Spintronic devices create spin-polarized currents and use the spin to control current flow.
SPINTRONICS
(APPLICATION OF NANOTECHNOLOGY)
ABSTRACT:
“Spintronics” is an emergent NANOtechnology, which uses the spin of an electron instead of or in addition to the charge of an electron. Electron spin has two states either “up” or “down”. Aligning spins in material creates magnetism. Moreover, magnetic field affects the passage of spin-up and spin-down electrons differently the paper starts with the detail description of the fundamentals and properties of the spin of the electrons. It proceeds with a note on magnetoresistance, the development of Giant Magnetoresistance (GMR) and devices like Magneto Random Access Memory, which are the new version of the traditional RAMs. It describe how this new version of RAMs which can revolutionize the memory industry. There is also detailed explanation of the way, how this revolution can increase the data density in our memory systems. It is followed by an account of new Spin Field Effect Transistors. It also specifies the differences between electronic devices and spintronic devices. It also gives the hurdles due to the presence of holes.
This paper also discusses about a quantum computer, which uses qubits rather than normal binary digits for computations. It also gives the hurdles due to the presence of holes.
Finally it ends with a note on why we should switch on this technology. Ran road track and conveyor belts kept the Ford’s assemble line running. At that time, his method of production was lauded and was considered most efficient. But that ford’s assembly plant, which was only eulogized in his time, will look strange to those who were born and raised up in the 21st century. Because the machines in the next 50 years will get increasingly smaller – so small that thousands of machines will fit into the full stop at the end of this line. This branch of engineering which deals with things smaller than 100 nanometres is termed as NANOtechnology. Eric Dexler first coined it in his book “engine of creation”.
In this paper we will discuss about a filed of Nanotechnology, which is believed to replace conventional electronics in the near future, i.e. “spintronics”.
History of Nanotechnology:
As nanoscience has advanced and discoveries in the field applied, the potential contributions of nanotechnology to future economic growth has brought increasing government attention. Today, nanotechnology is a top research priority of the Bush administration.
Attempts to coordinate federal work on the nanoscale began in November 1996, when staff members from several agencies decided to meet regularly to discuss their plans and programs in nanoscale science and technology. This group continued informally until September 1998, when it was designated as the Interagency Working Group on Nanotechnology (IWGN) under the National Science and Technology Council (NSTC).
The IWGN sponsored numerous workshops and studies to define the state of the art in nanoscale science and technology and to forecast possible future developments. Two relevant background publications were produced by the group between July and September 1999: Nanostructure Science and Technology: A Worldwide Study, a report based on the findings of an expert panel that visited nanoscale science and technology laboratories around the world; and Nanotechnology Research Directions, a workshop report with input from academic, private sector, and government participants. These documents laid the groundwork and provided the justification for seeking to raise nanoscale science and technology to the level of a national initiative.
In August 1999, IGWN completed its first draft of a plan for an initiative in nanoscale science and technology. The plan went through an approval process involving the President's Council of Advisors on Science and Technology (PCAST) and the Office of Science and Technology Policy . Subsequently, in its 2001 budget submission to Congress, the Clinton administration raised nanoscale science and technology to the level of a federal initiative, officially referring to it as the National Nanotechnology Initiative (NNI).
The National Nanotechnology Coordination Office (NNCO) was established to serve as the secretariat for the NSET, providing day-to-day technical and administrative support. The NNCO supports the NSET in multiagency planning and the preparation of budgets and program assessment documents. It also assists the NSET with the collection and dissemination of information on industry, state, and international nanoscale science and technology research, development, and commercialization activities. The importance of a coordinated Federal program for nanotechnology R&D was given greater recognition in 2003 with the enactment of the 21st Century Nanotechnology Research and Development Act (Public Law 108-153).
A common thread between store age, medical, industrial & molecular
Nanotechnology is an exponential curve.
The goal of early nanotechnology is to produce the first nano-sized robot arm capable of manipulating atoms and molecules into a useful producer copies of itself. Nano assembler working atom by atom would be rather slow because most desirable products are made of billions & trillions of atoms. However, an assembler robotarm could make copies of itself and those copies make copies. Then we have trillions of assemblers controlled by nano-super computers working in parallel assembling objects quickly.
What is Nanotechnology ???
Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale.
At the nanoscale, the physical, chemical, and biological properties of materials differ in fundamental and valuable ways from the properties of individual atoms and molecules or bulk matter. Nanotechnology R&D is directed toward understanding and creating improved materials, devices, and systems that exploit these new properties.
One area of nanotechnology R&D is medicine. Medical researchers work at the micro- and nano-scales to develop new drug delivery methods, therapeutics and pharmaceuticals. For a bit of perspective, the diameter of DNA, our genetic material, is in the 2.5 nanometer range, while red blood cells are approximately 2.5 micrometers. Additional information about nanoscale research in medicine is available from the National Institutes of Health. A nanometer is one-billionth of a meter; a sheet of paper is about 100,000 nanometers thick. See The Scale of Things for a comparative view of the sizes of commonly known items and nanoscale particles.
SPINTRONICS:
Imagine a data storage device of the size of an atom working at a speed of light. Imagine a microprocessor whose circuits could be changed on the fly. One minute is could be optimized for data base access. The next for transaction processing and the next for scientific number crunching. Finally, imagine a computer memory thousands of times denser and faster than today’s memories.
The above-mentioned things can be made possible with the help of an exploding science – “spintronics”.
Spintronics is a NANO technology which deals with spin dependent properties of an electron instead of or in addition to its charge dependent properties,.
Conventional electronics devices rely on the transport of electric charge carries-electrons. But there is other dimensions of an electron other than its charge and mass i.e. spin. This dimension can be exploited to create a remarkable generation of spintronic devices. It is believed that in the near future spintronics could be more revolutionary than any other thing that nanotechnology has stirred up so far.
WHY IS IT GOING TO BE ONE OF THE RAPIDLY EMERGING FIELDS?
As there is rapid progress in the miniaturization of semiconductor electronic devices leads to a chip features smaller than 100 nanometers in size, device engineers and physists are inevitable faced with a looming presence of a quantum property of an electron known as spin, which is closely related to magnetism. Devices that rely on an electron spin to perform their functions from the foundations of spintronics.
Information-processing technology has thus far relied on purely charge based devices ranging from the now quantum, vaccum tube today’s million transistor microchips. Those conventional electronic devices move electronic charges around, ignoring the spin that tags along that side on each electron.
ELECTRON SPIN:
FUNDAMENTALS OF SPIN
1. In addition to their mass and electric charge, 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.
3. Scientists represent the spin with a vector. For a sphere spinning “west to east”, the vector points “north” or “up”. It points “down” for the opposite spin.
4. In a magnetic field, electrons with “spin up” and “spin down” have different energies.
5. In an ordinary electronic circuit the spins are oriented at random and have no effect on current flow.
6. Spintronic devices create spin-polarized currents and use the spin to control current flow.
