If systems with larger numbers of ions are desired, the restricted cooling power necessitates the need for additional cooling, such as sympathetic cooling with co-trapped laser-cooled ions.
Cool, dignified, sympathetic and demanding, she knew that the result of her teaching (whether or not the grade-schoolers could play) was more public and visible than the more private family matter of, say, whether one's child could read.
Maier's eye was extraordinarily true — at once cool and sympathetic, with an instinctive sense of her subjects' place within the frame, and of the dignity that such a place bestowed.
Since her mom has already gone on the record with the "lame and annoying" decision, I can come out of this looking like the cooler, more sympathetic parent.
In this respect these Rydberg-Stark deceleration techniques represent one of several direct approaches to the preparation of chemically important cold molecules [26, 27], others include multistage Stark deceleration [12, 14], multistage Zeeman deceleration [21 23], optical Stark deceleration [28], buffer gas cooling [29, 30], and sympathetic cooling of molecular ions [31, 32].
Typically, our experiments run in this mode, where laser-cooled atomic ions provide sympathetic cooling of the molecular ion motion and the neutral buffer gas provides cooling of the molecular internal states as described in the next section.
Then sympathetic cooling by the laser-cooled ions can easily overcome these effects.
The similar recooling times for Ni=1 are evidence of the sympathetic cooling power of the laser-cooled buffer gas, but technically should not be considered evidence of regime I since Qi i(Ni=1)=0.
These two factors combined suggest that sympathetic cooling with ultracold atoms is particulary effective for cooling of charged molecules, which can be trapped with ion trapping technology [20], yielding a large and state-independent trap depth.
For sympathetic cooling experiments the most practical implication is that it is very difficult to cool a large number of ions (N i >30) to the solid phase using only buffer gas cooling.
