2024-03-28T20:09:32Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/213492016-02-16T06:30:09Zcom_10261_135com_10261_4col_10261_388
Long-lasting molecular alignment: Fact or fiction?
Ortigoso, Juan
RodrÃguez, Mirta
Santos, Julio
Karpati, Attila
Szalay, Viktor
13 pages, 10 figures, 1 appendix.
It has been suggested that appropriate periodic sequences of laser pulses can maintain molecular alignment for arbitrarily long times [J. Ortigoso, Phys. Rev. Lett. 93, 073001 (2004)]. These aligned states are found among the cyclic eigenstates of truncated matrix representations of the one-period time propagator U(T,0). However, long time localization of periodic driven systems depends on the nature of the spectrum of their exact propagator; if it is continuous, eigenstates of finite-basis propagators cease to be cyclic, in the long time limit, under the exact time evolution. We show that, for very weak laser intensities, the evolution operator of the system has a point spectrum for most laser frequencies, but for the laser powers needed to create aligned wave packets it is unknown if U(T,0) has a point spectrum or a singular continuous spectrum. For this regime, we obtain error bounds on the exact time evolution of rotational wave packets that allow us to determine that truncated aligned cyclic states do not lose their alignment for millions of rotational periods when they evolve under the action of the exact time propagator.
2010-02-19T09:33:56Z
2010-02-19T09:33:56Z
2010-02-17
artÃculo
Journal of Chemical Physics 132(7): 074105 (2010)
0021-9606
http://hdl.handle.net/10261/21349
10.1063/1.3312533
eng
http://dx.doi.org/10.1063/1.3312533
openAccess
American Institute of Physics