temperature scale titan ultracold atomic gases superfluid he

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