Azimuthal Sisyphus effect for atoms in a toroidal all-optical trap

Abstract

It is shown that an optical arrangement in which two identical counterpropagating Laguerre-Gaussian doughnut beams LG(l,0) and LG(-l,0) with orthogonal linear polarizations e {sub x} and e {sub y} can lead to azimuthal polarization gradients and an as yet undiscovered azimuthal Sisyphus effect. It is demonstrated that this effect can be utilized in the creation and control of a persistent current of superfluid atoms circulating in a toroidal trap. Such a physical system has recently been highlighted as the basis for an atomic superconducting quantum interference device (SQUID) and ultimately for the realization of atom circuits.