Sisyphus Cooling Justin M. Brown November 8, 2007

Sisyphus Effect Jean Dalibard and Claude Cohen-Tannoudji (1989) Model to describe sub-Doppler cooling Real atoms have more than two levels Atoms always travel up a hill to decrease KE

Sub-Doppler Cooling Doppler Limit Consider Atomic Zeeman Structure Approach Recoil Limit

Polarization Gradient Counter-propagating perpendicular linear polarizations Polarization Gradient from lightshifts

Lightshifts

Limitations Must Doppler cool first! –Only works over narrow range of velocities –Traveling over multiple potential hills averages out Doesn’t work if KE > U hill Detune laser further and reduce intensity Cannot break recoil limit – always emit photon

Experimental Implementation Miller, K. W., Durr, S, and Weinman, C. Rf-induced Sisyphus cooling in an optical trap. Phys. Rev. A, 66(023406), August Rubidium in an optical dipole trap Circular polarization pumps to end state

Experimental Implementation Miller, K. W., Durr, S, and Weinman, C. Rf-induced Sisyphus cooling in an optical trap. Phys. Rev. A, 66(023406), August 2002.