Comparing cavity and ordinary laser cooling within the Lamb–Dicke regime

Abstract

Cavity-mediated cooling has the potential to become one of the most efficient techniques to cool molecular species down to very low temperatures. In this paper we analyse cavity cooling with singlelaser driving for relatively large cavity decay rates κ and relatively large phonon frequencies ν. It is shown that cavity cooling and ordinary laser cooling are essentially the same within the validity range of the Lamb-Dicke approximation. This is done by deriving a closed set of rate equations and calculating the corresponding stationary state phonon number and cooling rate. For example, when ν is either much larger or much smaller than κ, the minimum stationary state phonon number scales as κ 2 /16ν 2 (strong confinement regime) and as κ/4ν (weak confinement regime), respectively.

Rate-equation approach to cavity-mediated laser cooling

“…This paper reconsiders a standard scenario for cavitymediated laser cooling [38][39][40][41][42][43]. As illustrated in Fig.…”

“…[38][39][40][41][42][43], we describe the time evolution of the experimental setup in Fig. 1 with the help of a quantum optical master equation.…”

“…1 and 2 which has already been studied by many authors [27,28,35,36,[39][40][41][42][43][44][45][46][47]. Analogously to ordinary laser cooling [48][49][50], the effective cooling rate of cavity-mediated laser cooling scales as the Lamb-Dicke parameter η squared.…”

“…The analysis of cavity-mediated laser cooling based on a master equation approach was pioneered by Cirac et al [38] in 1993. Subsequently, this approach has been used by many authors [39][40][41][42][43], since the precision of its calculations is easier to control than the precision of semiclassical calculations. Moreover, cavity-mediated cooling is especially then of practical interest when it allows particles to be cooled to very low temperatures, where quantum effects dominate the time evolution of the system and semiclassical models no longer apply [28].…”

New cooling mechanisms for atoms and molecules

“…The following contributions address a wide range of aspects of cooling, including buffer gas and cavity-mediated cooling. They report recent experiments [1,2] as well as recent theoretical progress towards an improved understanding and the identification of optimal routes to practicality [3][4][5][6]. We especially highlight close connections between theory and experiment in the development of new cooling mechanisms, which will ensure their development as broad enabling technologies with applications which range from quantum information processing and metrology to coherent molecular physics and chemistry.…”