Electronics Spectra - SMS Lucknow

SMS Institute of Technology, L ucknow
Department of Electronics & Co mmunication
swer for them under “any circumstances”.
• Points (upto 5%) may be deducted
from the total points of a
candidate if his/her handwriting is
not easily legible.
• Put in a serious and sincere e f-
fort.
o
Marks are not allotted for
mere superficial knowledge.
Orderly, effective and exact
expression combined with
due economy of words will be
rewarded.
• SI units will be used in the papers
and Candidates should use only
International form of Indian n u-
merals (i.e. 1,2,3,4,5,6 etc.) while
answering question papers.
• The Commission have discretion
to fix qualifying marks in any or all
the subjects of the examination.
o
Quantum mirage
The Objective Type papers will
be evaluated first and evaluation
of the Conventional
type papers is done only for
those candidates who obtain
the minimum qualifying marks
in Objective types papers, as
fixed by the Commission.
• Strongly Prepare general abili ty
Question Paper.
• Solve the previous years Question
Paper.
• Set the timing for every section-
’time is a big key’.
• Solve confidentally.
• Prefer best books.
• Prefer short, confident techniques
for saving time.
• Prepare for interview.
SUGGESTED BOOKS
1. Electronics Devices and Circuit &
Analog Electronics
o Microelectronic circuit –
SEDRA & SMITH.
o Solid State Electronic Devices
– STREETMAN & BANERJEE.
2. Communication System
o Mordern Digital & Analog
Communication – B.P.LATHI.
o Electronic Communication
System – KANNEDYAND
DEVIS.
3. Signal & System – OPPENHEIN &
WILLSKY.
4. Control System – B.S.MANKKE.
5. Electromagnetic Theory
o Elements of Electromagnetic
– SADIKU.
o Antenna & Wave Propagation
– K.D.PRASAD.
6. Digital Electronics
o
Digital Design – M.MORRIS
MANO.
o Mordern Digital Electronic –
R.P.JAIN.
SUGGESTED WEBSITES
www.upsc .com
www.onestopgate.com
Priya Srivastava
EC - III year
Since it first appeared on the cover
of Nature in February 2000, th e
“quantum mirage" has featured on
posters, calendars, websites and the
covers of various books and ma gazines.
The image - which was obtained
using a scanning tunnelling microscope
- shows the electronic wave functions
inside an elliptical "quantum corral"
made of cobalt atoms on a copp er
surface. It was created by Har i
Manoharan, Christopher Lutz and Don
Eigler of the IBM Almaden Rese arch
Center in California. In 1990, working
with Erhard Schweizer, Eiger spelt out
the letters "IBM" using 35 xenon atoms.
And three years later, wo rking
with Lutz and Michael Crommie, he
released the first images of the "quantum
corral", which have also been reproduced
in numerous places.
All moving particles have a wavelike
nature. This is rarely significant on
an everyday scale. But in atom ic dimensions,
where distances are measured
in nanometers, moving particles
behave like waves. This phenomenon
is what makes the electron mic roscope
workable. It is of inter est to
researchers in nanotechnology, who
are looking for ways to deliver electric
currents through circuits too small for
conventional wiring. The term quantum
mirage refers to a phenomenon
that may make it possible to transfer
data without conventional elec trical
wiring. Instead of forcing charge carriers
through solid conductors, a process
impractical on a microscopic scale,
electron wave phenomena are made
to produce effective currents.
A quantum mirage is a peculiar result
in quantum chaos. Every system
of quantum dynamical billiards will exhibit
an effect called scarring, where
the quantum probability density shows
traces of the paths a classical billiard
ball would take. For an elliptical arena,
the scarring is particularly pronounced
at the foci, as this is the region where
many classical trajectories converge.
The scars at the foci are coll oquially
referred to as the "quantum mirage".
They are two dimensional struc -
tures built atom by atom (usin g approximately
30-80 atoms) on at omically
smooth metallic surfaces using a
scanning tunneling microscope (STM).
Once the corrals are built, th e STM
can be used to study these nan ometer
scale structures with atomic resolution
in space and better tha n meV
(micro electron Volt) resolution in energy.
The data of the STM can be
rendered in false color to pro duce
breathtaking images that reveal standing
wave patterns of coherent electrons
inside the corrals.
The presence or absence of a
quantum mirage might be used t o
represent one bit of data in a region
far smaller than any current electronic
device can manage. It has the potential
to enable data transfer within future
nano-scale electronic circuits so
small that conventional wires do not
work.
IBM scientists are hoping to use
quantum mirages to construct atomic
scale processors in the future.
21 Electronics Spectra, 2010