Quantum experiments with macroscopic mechanical objects

Recent achievements in the isolation of macroscopic mechanical objects from a heat bath make it possible to implement quantum measurements with such s ystems. In this case, either a free mass or an oscillator can be used as a test object. The advantage of the first variant is in significantly longer relaxation times achieved for free masses. The advantage of the second vari ant is in the absence of restrictions on the limiting measurement accuracy associated with internal losses in the meter. This restriction can be bypas sed, retaining a long relaxation time typical of free masses, if a test osc illator with a ponderomotive electromagnetic rigidity is used. Estimates sh ow that the potential sensitivity of this test body for the modem level of technology may be considerably higher than the standard quantum limit. (C) 2001 MAIK "Nauka/Interpetiodica".