An Alternative to Laser Cooling

Eugene K. Bashkirov, Башкиров Е. К

The process of laser cooling of an extended impurity crystal in a superradiance regime is explored with using the alternative scheme of a pumping of the impurity ions. Possibility of cooling of samples at the expense of collective radiation is shown.

Ignacio Enrique Olivares Bahamondes, Patrick Carrazana

Naomy Duarte Gomes, M. A. Caracanhas, Kílvia Mayre Farias +1 more

The technique of laser cooling, whose basic idea was proposed in 1975 [1], provided the development of many important areas like high-resolution spectroscopy [2], atomic clocks [3] and quantum gases confined in magnetic or optical traps [4, 5]. Among the techniques applied to cooling neutral atoms is the optical molasses [6] that will be explored in this work. Here we study the standard molasses and a new alternated molasses configuration, which consists of turning on just one pair of counter-propagating laser beams per cycle, and alternating this pair between the three spatial directions. We analyse the two techniques under the lens of the radiation force, by exploring a semiclassical treatment, in order to obtain the minimum energy attained by each of them at the end of the cooling process. We compare, then, these two cooling techniques, pointing out their advantages.

Pierre Meystre

Guang-Zong Dong, Xinlu Zhang, Jinhui Cui

We propose an alternative excitation scheme based on paired-π-pulse input for laser cooling of solids in the superradiance regime. The dynamics of the activated atoms being pumped is analyzed, and used to deduce the temperature-dependent cooling power. Compared with the continuous-wave plus pulse pumping scheme, our scheme works better for laser cooling of solids via superradiance, and can improve the cooling power by 4 and 50 times at room and cryogenic temperatures, respectively.

José Tito Mendonça, Hugo Terças