19 research outputs found
Chaos, entanglement and decoherence in the quantum kicked top
We analyze the interplay of chaos, entanglement and decoherence in a system
of qubits whose collective behaviour is that of a quantum kicked top. The
dynamical entanglement between a single qubit and the rest can be calculated
from the mean of the collective spin operators. This allows the possibility of
efficiently measuring entanglement dynamics in an experimental setting. We
consider a deeply quantum regime and show that signatures of chaos are present
in the dynamical entanglement for parameters accessible in an experiment that
we propose using cold atoms. The evolution of the entanglement depends on the
support of the initial state on regular versus chaotic Floquet eigenstates,
whose phase-space distributions are concentrated on the corresponding regular
or chaotic eigenstructures. We include the effect of decoherence via a
realistic model and show that the signatures of chaos in the entanglement
dynamics persist in the presence of decoherence. In addition, the classical
chaos affects the decoherence rate itself.Comment: 11 pages, 9 figure