We systematically investigate the polarization gradient cooling(PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequency is stepped to the setting value while its intensity is ramped, is found to be the best for the PGC, compared with other modes studied. We verify that the heating effect of the cold atoms, which appears when the cooling laser intensity is lower than the saturation intensity, arises from insufficient polarization gradient cooling. Finally, an exponential decay function with a statistical explanation is introduced to explain the dependence of the cold atom temperature on the PGC interaction time.We systematically investigate the polarization gradient cooling(PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequency is stepped to the setting value while its intensity is ramped, is found to be the best for the PGC, compared with other modes studied. We verify that the heating effect of the cold atoms, which appears when the cooling laser intensity is lower than the saturation intensity, arises from insufficient polarization gradient cooling. Finally, an exponential decay function with a statistical explanation is introduced to explain the dependence of the cold atom temperature on the PGC interaction time.

中国物理B：英文版Jan 1, 20140 citations

Cooling and Trapping

Juha Javanainen

Springer handbooksJan 1, 20230 citations

Perturbations

Edgard Elbaz

Springer eBooksJan 1, 19980 citations

Polarization-gradient cooling of 1D and 2D ion Coulomb crystals

Manoj K. Joshi, A Fabre, Christine Maier +5 more

Abstract We present experiments on polarization gradient cooling of Ca + multi-ion Coulomb crystals in a linear Paul trap. Polarization gradient cooling of the collective modes of motion whose eigenvectors have overlap with the symmetry axis of the trap is achieved by two counter-propagating laser beams with mutually orthogonal linear polarizations that are blue-detuned from the S 1/2 ↔ P 1/2 transition. We demonstrate cooling of linear chains of up to 51 ions and 2D-crystals in zig-zag configuration with 22 ions. The cooling results are compared with numerical simulations and the predictions of a simple model of cooling in a moving polarization gradient.Abstract We present experiments on polarization gradient cooling of Ca + multi-ion Coulomb crystals in a linear Paul trap. Polarization gradient cooling of the collective modes of motion whose eigenvectors have overlap with the symmetry axis of the trap is achieved by two counter-propagating laser beams with mutually orthogonal linear polarizations that are blue-detuned from the S 1/2 ↔ P 1/2 transition. We demonstrate cooling of linear chains of up to 51 ions and 2D-crystals in zig-zag configuration with 22 ions. The cooling results are compared with numerical simulations and the predictions of a simple model of cooling in a moving polarization gradient.

arXiv:2006.15104New Journal of PhysicsSep 16, 202044 citations

Cooling and Trapping

Juha Javanainen

Springer handbooksJan 1, 20061 citation

Polarization gradient cooling of single atoms in optical dipole traps

Yue-Sum Chin, Matthias Steiner, Christian Kurtsiefer

We experimentally investigate ${\ensuremath{\sigma}}^{+}\text{\ensuremath{-}}{\ensuremath{\sigma}}^{\ensuremath{-}}$ polarization gradient cooling (PGC) of a single $^{87}\mathrm{Rb}$ atom in a tightly focused dipole trap and show that the cooling limit strongly depends on the polarization of the trapping field. For optimized cooling light power, the temperature of the atom reaches $10.4(6)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ in a linearly polarized trap, approximately five times lower than in a circularly polarized trap. The inhibition of PGC is qualitatively explained by the fictitious magnetic fields induced by the trapping field. We further demonstrate that switching the trap polarization from linear to circular after PGC induces only minor heating.We experimentally investigate ${\ensuremath{\sigma}}^{+}\text{\ensuremath{-}}{\ensuremath{\sigma}}^{\ensuremath{-}}$ polarization gradient cooling (PGC) of a single $^{87}\mathrm{Rb}$ atom in a tightly focused dipole trap and show that the cooling limit strongly depends on the polarization of the trapping field. For optimized cooling light power, the temperature of the atom reaches $10.4(6)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ in a linearly polarized trap, approximately five times lower than in a circularly polarized trap. The inhibition of PGC is qualitatively explained by the fictitious magnetic fields induced by the trapping field. We further demonstrate that switching the trap polarization from linear to circular after PGC induces only minor heating.

arXiv:1707.05965Physical Review ASep 7, 201717 citations

We experimentally investigate ${\ensuremath{\sigma}}^{+}\text{\ensuremath{-}}{\ensuremath{\sigma}}^{\ensuremath{-}}$ polarization gradient cooling (PGC) of a single

^{87}\mathrm{Rb}

atom in a tightly focused dipole trap and show that the cooling limit strongly depends on the polarization of the trapping field. For optimized cooling light power, the temperature of the atom reaches $10.4(6)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ in a linearly polarized trap, approximately five times lower than in a circularly polarized trap. The inhibition of PGC is qualitatively explained by the fictitious magnetic fields induced by the trapping field. We further demonstrate that switching the trap polarization from linear to circular after PGC induces only minor heating.