Atomically%20Thin%20Carbon::

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Atomically Thin Carbon
From Revolutionary Electronics to
the Core of Neutron Stars
Antonio H. Castro Neto
Aspen Center for Physics June, 2008
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Our collaborators around the world
Kostya Novoselov, Manchester, U.K.
Marcos Pimenta, UFMG Brazil
Joao Lopes dos Santos, Univ. Porto
Portugal
Francisco Guinea, ICMM Spain
Fernando Sols, Univ. Complutense
Spain
Johan Nilsson, Leiden Univ. The Netherlands
Javier Sabio, ICMM Spain
Chiung-Yuan Lin, NCTU Taiwan
Alessandra Lanzara, Berkeley USA
Shuyun Zhou, Berkeley USA
Eun-Ah Kim, Stanford USA
Vitor Pereira, BU USA
Bruno Uchoa, BU USA
Silvia Viola, BU USA
Valeri Kotov, BU USA
Caio Lewenkopf, UERJ Brazil
Nuno Peres, Univ. Minho Portugal
Eduardo Castro, Univ. Porto Portugal
Tobias Stauber, Univ. Minho Portugal
Eduardo Mucciolo, UCF USA
Andre Geim, Manchester, U.K.
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The Ig Nobel Prizes honor achievements that first
make people laugh, and then make them think. The
prizes are intended to celebrate the unusual,
honor the imaginative -- and spur people's
interest in science, medicine,and technology.
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Why geckos can walk upside down on a glass
window ?
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Gecko tape
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The bad and the ugly
Why carbon ?
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The good and beautiful
Diamond Graphite
Beauty and the Beast
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C20 C60 C540
Fullerenes or Buckyballs zero dimensional
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The making of a fullerene
1. Take graphene
3. Add a few more!
2. Add a pentagon
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Carbon Nanotubes one dimensional
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The making of carbon nanotubes
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Beautiful and useful !
Microscopic electric cables Nanomechanical
Resonators Chemical sensors
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Graphite
Stacked graphene!
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The English had a monopoly on the production of
pencils. In 1795, Nicholas Jacques Conte (a
French officer in Napoleon's army) patented the
modern method of kiln-firing powdered graphite
with clay to make graphite rods for pencils. By
varying the ratio of graphite to clay, the
hardness of the graphite can also vary.
In ancient times pencils" consisted of a thin
rod composed of soft lead, and were used mostly
by artists. The word pencil comes from the
Latin word "penicillus," which means "little
tail" - the name of the tiny brush that ancient
Romans used as a writing instrument.
Fun facts about pencils !
The "lead" pencil (which contains no lead) was
invented in 1564 when a huge graphite mine was
discovered in Borrowdale, Cumbria, England. They
were called lead pencils by mistake.
Graphite (named for the Greek word meaning "to
write") was chemically analyzed in 1779 by K.W.
Scheele and named in 1789 by A.G. Werner.
Graphene is easy to make, but hard to find
!!!
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From 1564 to 2004 !
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Recipe for making a graphene transistor
by Philip Kim
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Plus some nanotechnology
2?m

• optical image

• SEM image

• design

• contacts and mesa

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What is so special about graphene ?
Fermions
Normal conductor
Graphene
Dirac fermions
But how ???
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Quantum Mechanics
Wave-particle duality
particle
wave
Interference
Dirac fermions are the final result!
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What is the proof that Dirac fermions exist in
graphene?
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QHE papers appear on Nature
Novoselov et al.. appears on Science
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Electrons propagate just as light does.
Relativity at very low speed of light
Weirdness of Quantum Physics plus Relativity!

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Collision with a barrier
Classical
R1
Quantum
Rlt1,Tlt1 RT1
Relativistic Quantum
T1
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Atomic Physics
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Atomic Physics
Z
Z
Overcritical Atom
Z
Positron emission
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Some interesting consequences
Anthropic principle argues that the value of the
fine-structure constant is what it is because
stable matter and therefore life and intelligent
beings could not exist if the value were anything
else. For instance, were the fine structure
constant to change by 4, carbon would no longer
be produced in stellar fusion. If the fine
structure constant were greater than 0.1, fusion
would no longer occur in stars.
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heavy ion collisions neutron stars
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But in graphene
Atoms become overcritical easily
Z
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V
Use a scanning tunneling microscope,for a
high- energy experiment
I
Resonances indicate emission of
anti-particles
V
V
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Graphene is a soft material
Relativistic particles propagate in curved
space

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Now Let us go back to Earth
What about applications ?
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Tukwila (Intel) February 2008 2 billion
transistors speed 2 GHz 65 nm transistors
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Graphene Quantum Dots
Miniaturization down to 1 nm a few benzene rings
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The rise of graphene Much more to come .