title: Quantum control by compensation of quantum fluctuations.
abstract: 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 emissions for a specific state of the atomic system allowing complete control of the coherent state of the system.
authors.forename: H
authors.initials: H
authors.lastname: Hofmann
authors.forename: O
authors.initials: O
authors.lastname: Hess
authors.forename: G
authors.initials: G
authors.lastname: Mahler