Temperature scale
description
Transcript of Temperature scale
Temperature scale
Titan
Ultracold atomic gases
Superfluid He
Quantum mechanics in action
1) Particle-Wave duality
h
p mvp de Broglie wave-length
(de Broglie 1923)momentum
sec106.6
227 cm
gh
Planck constant (1900)
When confinement is present only certain modes are allowed, i.e., certain energies (levels).
Bose-Einstein statistics (1924) Fermi-Dirac statistics (1926)
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”
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
only thermal only BECboth thermaland BEC
thermal
Temperature measured thruogh thermal component tails
"for the achievement of Bose-Einstein 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
"for development of methods to cool and trap atoms with laser light"
Physics Nobel Prizes
1997 2001
Steven Chu Claude Cohen-Tannoudji
William D. Phillips
Optical Lattices
1D dynamics, (Fermi/Bose) Hubbard model description, Mott insulating phase…
Laser standing wave
1D (optical) lattice
Periodic potential via the dipole force
Deeper (3D) optical lattices: quantum phasetransition from superfluid to Mott insulator (I. Bloch et al., Nature 2002)
Atoms move around, delocalized on
many lattice site
Atoms are localized on
a single lattice site
Incresing the lattice strength