Laser Cooling Atom Lasers Seth A M

Laser Cooling & Atom Lasers Seth A. M. Aubin Dept. of Physics College of William and Mary November 13, 2010 Laser. Fest 2010, Small Hall Open House

Outline Ø What’s special about LASER light? Ø Laser cooling & Ultracold Matter. Ø Atom Lasers

What’s special about LASER light?

What’s special about LASER light? Ø Light consists of waves.

What’s special about LASER light? Ø Light consists of waves. Ø In a LASER: All the light waves are the same. All the light waves are in sync.

Light as a wave LASER source Screen

Light as a wave LASER source screen

Also works for single photons !!! [A. L. Weiss and T. L. Dimitrova, Swiss Physics Society, 2009. ]

… Perhaps, Matter is a

Laser light is COLD Thermal Physics: COLDER = more order HOTTER = less order

Laser light is COLD Thermal Physics: COLDER = more order HOTTER = less order LASER light is very ordered very COLD

Laser Cooling Lab frame v Atom’s frame Lab frame, after absorption v-vrecoil Ø Absorb a photon atom gets momentum kick. Ø Repeat process at 107 kicks/s large deceleration. Ø Emitted photons are radiated symmetrically do not affect motion on average

Magneto-Optical Trap (MOT)

Magneto-Optical Trap (MOT) ~ 100 K

How cold can you go? 1000 K room temperature, 293 K Antarctica, ~ 200 K K m. K Dilution refrigerator, ~ 2 m. K [priceofoil. org, 2008] LASER COOLING ~ 100 K μK Ultra-cold quantum temperatures n. K

Bose-Einstein Condensate COLDER Ultra-COLD

Bose-Einstein Condensate COLDER COLD ~ n. K 00 5 Ultra-COLD

BEC History 1925: 1924: S. N. Bose describes the statistics of identical boson particles. A. Einstein predicts a low temperature phase transition, in which particles condense into a single quantum state. 1995: E. Cornell, C. Wieman, and W. Ketterle observe Bose. Einstein condensation in 87 Rb and 23 Na.

BEC: Atom Laser

BEC: Atom Laser [data from Thywissen group, U. of Toronto]