|
Quantum Theory
and Nano Technology are natural partners with great
potential applications in the context of Computing
Systems. Ironically, although the quantum theory is almost
emerging as the most successful theory ever proposed in
the scientific literature (often accurate to within one
part in 10 billion), it can give only probabilities of any
object, existing as the superposition of many possible
states, rather than definite hard answers to problems as
expected from Newtonian theory of "objective reality" in
which each object existed in a definite state. However, we
have nanotechnology and can manipulate individual atoms,
so atoms that pop in and out of existence can be
manipulated at will, using scanning tunneling microscope.
Accordingly, there should be no invisible "wall"
separating the microscopic and macroscopic world but
rather a continuum.
One
of the best descriptions of the field is the classic talk
that the great physicist, Richard Feynman gave on December
29th 1959 at the annual meeting of the American
Physical Society at the California Institute of Technology
(Caltech) :
"If we wanted to make a
computer that had all these marvelous extra qualitative
abilities, we would have to make it, perhaps, the size of
the Pentagon. This has several disadvantages. First, it
requires too much material; there may not be enough
germanium in the world for all the transistors which would
have to be put into this enormous thing. There is also the
problem of heat generation and power consumption; TVA
would be needed to run the computer. But an even more
practical difficulty is that the computer would be limited
to a certain speed. Because of its large size, there is
finite time required to get the information from one place
to another. The information cannot go any faster than the
speed of light---so, ultimately, when our computers get
faster and faster and more and more elaborate, we will
have to make them smaller and smaller. "
Quantum computers will perform computations at the atomic
scale. We might ask how close conventional computations
are to this scale already? Figure shows a survey made by
Keyes in 1988: The number of dopant impurities in the
bases of bipolar transistors used for digital logic
against the year. This plot may be thought of as showing
the number of electrons required to store a single bit of
information. An extrapolation of the plot suggests that we
might be within reach of the atomic-scale computations
within the next two decades.
The number of
dopant impurities in the bases of bipolar transistors
Conventional
computers have been improving in speed and miniaturization
at an exponential rate since their earliest days. Clearly
there is a bound to our ability to miniaturize
conventional electronics and we will likely be touching
that limit within the next ten to twenty years. The
question is raised, can we continue to expect to see an
exponential improvement in performance twenty and more
years from now? As we approach some of the physical limits
to conventional computational construction we may begin to
see a slow-down of this exponential rate. A detailed study
of quantum computation may help us understand the
fundamental physical limitations upon computation,
conventional or otherwise
While quantum information science is a broad and rapidly
expanding field, there are a few underlying recurrent
themes. The theory of classical information, computation,
and communication developed extensively during the
twentieth century. Though undeniably useful, this theory
cannot fully characterize how information can be used and
processed in the physical world - a quantum world. Some
achievements of quantum information science can be
described as generalizations or extensions of the
classical theory that apply when information is
represented as a quantum state rather than in terms of
classical bits. The well-established theory of classical
information and computation is actually a subset of a much
larger topic, the emerging theory of quantum information
and computation.
There is a worldwide effort in progress to spur
nanotechnology and it is receiving increasing attention
the world over in the last few years. Next ten years will
see nanotechnology playing the most dominant role in the
global business environment and is expected to go beyond
the billion dollar estimates and cross the figure of $ one
trillion. Focused programmes on nanotechnology have been
launched by several nations. It is estimated that 2
million workers will be needed to support nanotechnology
industries worldwide within 15 years. We have to train
students, teachers and research scholars. Unless we do
this, there will not be enough work happening in this area
in the near future.
India is emerging as a global leader in the
nanotechnology field and is a significant player in
contributing to the development of new technologies
besides carrying out basic research at the frontiers.
Former President Dr. A.P.J. Abdul Kalam has envisioned,
"Nanotechnology is knocking at our doors. . . Molecular
switches and circuits along with nano cell will pave the
way for the next generation computers. . . With the
emergence of Nanotechnology, there is convergence of nano-bio-info
technologies resulting in new devices which has wider
applications in structure, electronics, and healthcare and
space systems. Potential applications are virtually
endless. Progress in nanotechnology is spurred by
collaboration among researchers in material science,
mechanical engineering, computer science, molecular
biology, physics, electrical engineering, chemistry,
medicine and aerospace engineering. This is one of the
important emerging area which brings synergy in research
and development by combining the strengths of the multiple
domain knowledge leading to the creation of knowledge
society. Our educational institutions and universities
should have special purpose missions based on their core
competence."
Inspite
the large amount of research and development, there are
not many opportunities for exposing our students to these
frontier areas. The Quantum and Nano Computing research
group at DEI and IIT Kanpur has jointly authored entry
level textbooks [1,2] which provide a smooth passage to
our students from the classroom to the quantum and
nanotech laboratories. The books deal with several issues
starting with the basics of quantum and nano computing,
qubits, gates, nanotubes, and gradually expose them to the
frontline areas of research in these areas.
References
1. Sahni V.,
Quantum Computing, McGraw Hill Education (Asia), 2007,
ISBN 978-007062095-7.
|
