  Measurement feedback is a versatile and powerful tool, although its
performance is limited by several practical imperfections resulting from
classical components. This paper shows that, for some typical quantum feedback
control problems for state preparation (stabilization of a qubit or a qutrit,
spin squeezing, and Fock state generation), the classical feedback operation
can be replaced by a fully quantum one such that the state autonomously
dissipates into the target or a state close to the target. The main common
feature of the proposed quantum operation, which is called coherent feedback,
is that it is composed of a series of dispersive and dissipative couplings
inspired by the corresponding measurement feedback scheme.

Quantum Physics