Excitation of pseudorotational vibronic motion through femtosecond pump-probe spectroscopy: A 2D computational study

The real-time excitation and detection of radial and pseudorotational vibro nic motions of Jahn-Teller and pseudo-Jahn-Teller coupled systems is studie d theoretically. A previously developed 2D description of ground and excite d electronic states of the sodium trimer, Ng, is employed as a realistic mo del system. Within this scheme the detection of vibronic motions proceeds b y measuring the ion signal, possibly resolved for the kinetic energy of the ejected photoelectrons. It is demonstrated how by changing Various pulse p arameters, such as pulse length, strength, or carrier frequency, radial or pseudorotational motions in the ground or excited electronic states are sel ectively excited. The particularly interesting-and difficult-case of exciti ng the pseudorotational motion in the ground state manifold can be realized by using three different pulses.