Download Diapositiva 1

Temperature scale
Titan
Superfluid He
Ultracold atomic gases
Quantum mechanics in action
1) Particle-Wave duality
p  mv
momentum
h

p
de Broglie wave-length
(de Broglie 1923)
h  6.6 10
 27
cm 2
g
sec
Planck constant (1900)
When confinement is present only
certain modes are allowed, i.e.,
certain energies (levels).
2) Quantum Statistics: bosons and fermions
“Bosons like
staying together,
i.e., in the same state”
“Fermions dislike
staying together,
i.e., in the same state”
Bose-Einstein statistics (1924)
Fermi-Dirac statistics (1926)
Dilute gases: 1995, JILA, MIT
Dilute gases: 1999, JILA
New state of matter…
W. Ketterle
One of the first BEC images (JILA 1995)
Below a certain temperature a macroscopic
atomic fraction occupies the lowest energy state
thermal
only thermal
both thermal
and BEC
only BEC
Temperature measured thruogh thermal
component tails
Physics Nobel Prizes
2001
1997
"for development of
methods to cool and trap
atoms with laser light"
Steven Chu
Claude
CohenTannoudji
William D.
Phillips
"for the achievement of BoseEinstein condensation in dilute
gases of alkali atoms, and for early
fundamental studies of the
properties of the condensates"
Eric A.
Cornell
Wolfgang
Ketterle
Carl E.
Wieman
Optical Lattices
Periodic potential via the dipole force
Laser standing wave
1D (optical) lattice
1D dynamics, (Fermi/Bose) Hubbard model description, Mott insulating phase…
Deeper (3D) optical lattices: quantum phase
transition from superfluid to Mott insulator
(I. Bloch et al., Nature 2002)
Atoms move around,
delocalized on
many lattice site
Incresing the
lattice strength
Atoms are
localized on
a single lattice site