Rate-equation approach to cavity-mediated laser cooling

Abstract

The cooling rate for cavity-mediated laser cooling scales as the Lamb-Dicke parameter η squared. A proper analysis of the cooling process hence needs to take terms up to η 2 in the system dynamics into account. In this paper, we present such an analysis for a standard scenario of cavity-mediated laser cooling with η 1. Our results confirm that there are many similarities between ordinary and cavity-mediated laser cooling. However, for a weakly confined particle inside a strongly coupled cavity, which is the most interesting case for the cooling of molecules, numerical results indicate that more detailed calculations are needed to model the cooling process accurately.

No-go theorem for ground state cooling given initial system-thermal bath factorization

“…While previous studies have pointed out the unattainability of the absolute zero of in such situations151617, here we isolate the centrality of the factorization assumption, and emphasize its strong implications regarding both the underlying physics and the suitability of master-equation type computational frameworks that often assume factorization, see e.g., Ref. 11,12,13,14.…”

“…As such, the goal is the ideal limiting case of many experiments in which the target is cooling to near the ground state. The result provides a formal proof with significant consequences for theoretical and computational studies11121314.…”

Cavity-mediated collective laser-cooling of a non-interacting atomic gas inside an asymmetric trap to very low temperatures

“…Instead of considering a symmetric harmonic trap, we place the particles into an asymmetric trapping potential. The cooling process that we propose here is qualitatively different from other laser cooling techniques [22][23][24][25][26][27][28] for which the final energy of the atoms is usually independent of the number N of particles inside the trap. In contrast to this, we predict a final mean phonon number which vanishes in the infinitely-many particle limit.…”

“…In 1993, Cirac et al [22] introduced a master equation approach to analyse cavity-mediated laser-cooling in more detail. Since the precision of calculations, which are based on master equations, is easier to control than the precision of semiclassical approximations, this approach has subsequently been used by many authors to emphasize a close analogy between laser-sideband and cavity-mediated laser-cooling of atomic particles [23][24][25][26][27][28].…”

Cooling a two-level emitter in photonic-crystal environments

“…Laser cooling of a trapped atom can be achieved in a optical cavity as well [2,5]. Cavitymediated laser cooling was further investigated in [6]. Dark-state laser cooling of a trapped ion using standing waves and cooling by heating in the quantum optics domain were recently discussed in [7] and [8], respectively.…”