Entanglement induced by nonadiabatic chaos (4 pages)

Barry C. Sanders, Shohini Ghose

Hiroshi Fujisaki

We investigate entanglement between electronic and nuclear degrees of freedom for a model nonadiabatic system. We find that entanglement (measured by the von Neumann entropy of the subsystem for the eigenstates) becomes nearly maximum when the system shows ``nonadiabatic chaos'' behavior which was found in our previous work [Phys. Rev. E 63, 066221 (2001)], but the reverse is not necessarily the case.

Hisashi Higuchi, Kazuo Takatsuka

The effect of nonadiabatic coupling due to breakdown of the Born-Oppenheimer approximation on chaos is investigated. A couple of measures (indicators) that detect the extent of chaos in wave-packet dynamics on coupled potential functions are devised. Using them, we show that chaos is indeed induced by a nonadiabatic coupling in individual time-dependent wave-packet dynamics. This chaos is genuinely of quantum nature, since it arises from bifurcation and merging of a wave packet at the quasicrossing region of two coupled potential functions.

Lock Yue Chew

Tobias Brandes, Clive Emary, Neill Lambert