  Quantum baker`s map is a model of chaotic system. We study quantum dynamics
for the quantum baker's map. We use the Schack and Caves symbolic description
of the quantum baker`s map. We find an exact expression for the expectation
value of the time dependent position operator. A relation between quantum and
classical trajectories is investigated. Breakdown of the quantum-classical
correspondence at the logarithmic timescale is rigorously established.
