Field cooled regime

Fig. 90. Neutron scattering intensity of Euo j Sro 4jS measured after zero-field cooling plotted as function of momentum transfer q,0,0)=Q-Q where = (2,0,0). Spectra at H = 0 and H = 41 mX are shown, each at a temperature in the FM-regime (r = 3.0K) and in the RSG-regime (r=0.5K). The right- and left-hand vertical scales are for the 3K (upper curves) and 0.5 K (lower curves) data, respectively. Solid curves correspond to eq. 101 (from Aeppli et al. 1986).

Prom this expression we can see that the friction coefficient depends only on the detuning of the laser field. Obviously, the friction coefficient imder conditions of polarization cooling, l3 = %k A/, can be considerably higher than the maximum friction coefficient in the Doppler-cooling regime, which is approximately... 

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