  This paper focuses on the coefficient of performance (COP) at maximum figure
of merit $\chi$ for a Brownian Carnot-like refrigerator, within the context of
symmetric Low-Dissipation approach. Our proposal is based on the Langevin
equation for a Brownian particle bounded to a harmonic potential trap, which
can perform Carnot-like cycles at finite time. We show that under quasistatic
conditions the COP has the same expression as the macroscopic Carnot
refrigerator. However, for irreversible cycles at finite time and under
symmetric dissipation, the optimal COP is the counterpart of Curzon-Ahlborn
efficiency for irreversible macroscopic refrigerators.
