From Lasers to Bose-Einstein condensates - University of St Andrews

106 Pages·2008·2.28 MB·English

From Lasers to Bose-Einstein condensates
How superfluids, superconductors, polaritons and lasers fit together
Jonathan Keeling
Stokes Society, November 2008
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 1/28
The two-slit experiment
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 2/28
The two-slit experiment
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 2/28
The two-slit experiment
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 2/28
The two-slit experiment
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 2/28
Macroscopic objects
Why no such interference for macroscopic objects?
√
Wavelength would be very small λ ∼ 1/ m
Internal degrees of freedom remember “which way”.
Different initial conditions wash out path.
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 3/28
Macroscopic objects
Why no such interference for macroscopic objects?
√
Wavelength would be very small λ ∼ 1/ m
Internal degrees of freedom remember “which way”.
Different initial conditions wash out path.
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 3/28
Macroscopic objects
Why no such interference for macroscopic objects?
√
Wavelength would be very small λ ∼ 1/ m
Internal degrees of freedom remember “which way”.
Different initial conditions wash out path.
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 3/28
Macroscopic objects
Why no such interference for macroscopic objects?
√
Wavelength would be very small λ ∼ 1/ m
Internal degrees of freedom remember “which way”.
Different initial conditions wash out path.
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 3/28
All atoms in single quantum state — like a classical wave.
The two-slit experiment with condensates
JonathanKeeling FromLaserstoBose-Einsteincondensates StokesSociety 4/28