Bose Einstein Condensation Condensed Matter II –Spring 2007
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Bu səhifədəki naviqasiya:
BEC in Dilute Gases and Liquid Helium
Some Theory More Theory
Interacting Particles: Gross-Pitaeviski Eq.
1995 – Wolfgang Ketterle Na23. (4 months later)
How to make a BEC Heat the atoms: 600 K (gas)
Evaporative Cooling Famous Picture
BEC achieved in several atoms.
Bose
Einstein Condensation
Condensed Matter II –Spring 2007
Davi Ortega
Summary
From counting to a new state of matter
Indistinguishability
of particles
Counting indistinguishable particles
Einstein’s conclusion =
New State
Some properties
BEC in
Dilute Gases and Liquid Helium
Experiments to achieve the BEC.
News
Statistics of Idea Gas
Two Particles Gas: A and B.
Some Theory
More Theory
Two
more useful results
An Last statement
This whole theory assume non interacting particles:
Schrödinger Equation
Interacting Particles: Gross-Pitaeviski Eq.
Achievements
1938 – Pyotr Kapitsa John Allen and Don Misener: Helium 4
1995 – Eric Cornell and Carl Wieman: Rb87: Pure BEC.
1995 – Wolfgang Ketterle Na23. (4 months later)
Liquid He vs. Diluted Gas
Strong Interactions in He qualitatively changes the nature of transition.
Diluted Gas
Pure
Condensate state
Liquid Helium
Zero Viscosity
And other strange properties.
How to make a BEC ?
Heat the atoms: 600 K (gas)
Confine
them in a beam
Decelerate the beam
Trap the atoms (Magneto Optical Trap)
Magnetic Trapping (avoid atoms recoil by spontaneous emission and random absorption)
Evaporative Cooling
Famous Picture
Any other way ?!
Current
Research
BEC achieved in several atoms.
Strange Properties:
Superfluidity
Slowing of light
Wave-like phenomena in atoms.
Interference between two condensates.
Atom Laser
Coherent
Matter Waves
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