We show that the influence of quantum fluctuations in the electromagnetic
field vacuum on a two level atom can be measured and consequently compensated
by balanced homodyne detection and a coherent feedback field. This compensation
suppresses the decoherence associated with spontaneous emission for a specific
state of the atomic system allowing complete control of the coherent state of
the system.Comment: 5 pages RevTex and 2 figures, to be published in Optics Expres