Simultaneous control of time-dependent population transfer dynamics and wave-packet quantum interferences inLi2by shaped ultrafast pulses

Abstract

Ultrafast pulse shapes are used to control simultaneously the optimal population transfer coefficients and rotational wave-packet quantum interferences in the E 1 ⌺ g ϩ state of Li 2 ( E ϭ9, J E ϭ27 and 29͒. By dividing the spectral bandwidth of the ultrafast pulses into multiple ''control domains'' centered on each resonant wavelength, the population transfer coefficients can be manipulated independently of the wave-packet interferences to maximize the Li 2 photoionization yield at arbitrary short pump-probe time delays. To investigate the population transfer coefficients with and without wave-packet interferences, respectively, the pump polarization is set to be either parallel to or at the magic angle ͑ϳ55°͒ relative to the probe polarization. A comparison is made between phases that are symmetric and antisymmetric about the resonances. The effects of resonant and nonresonant frequencies are separately established and quantified. It is estimated that up to 90% of the possible nonresonant Rabi oscillations can be brought into phase simultaneously for each rovibrational state in the wave packet, while at the same time a constant phase offset added to one of the control domains establishes the phase of the wave-packet interference.

Spin–orbit coupling of the NaK 33Π and 31Π states: Determination of the coupling constant and observation of quantum interference effects

“…Such interference effects form the basis of many interesting phenomena including most quantum control schemes [53][54][55][56][57][58][59][60][61][62][63][64].…”

Coherent interaction of femtosecond extreme-uv light with He atoms

“…In the near infrared (800 nm) regime, ultra-short laser pulses are routinely used for coherent control of atomic and molecular quantum processes [1][2][3]. In particular, shaping of the spectral phase of fs pulses is used to selectively enhance [4][5][6] or attenuate [7] resonant vs. nonresonant pathways of multi-photon absorption in Rb atoms. Coherent control of fundamental systems systems such as the He atom requires access to fs pulses in the extreme-UV (EUV) regime.…”

“…For an exciting pulse with a symmetric spectral content and phase about the resonant frequency, the nonresonant term vanishes for short times as well, since the blue shifted components cancel the contribution of the red shifted components. As the nonresonant term depends strongly on the symmetry of the exciting pulse, coherent manipulation of the spectral phase can alter or control the transient amplitude, as was demonstrated by using various pulse shaping schemes in the infrared regime [4][5][6][7]21]. One of the techniques for spectral phase manipulation is the propagation of a pulse through a "resonant filter" medium with one or more absorption resonances [4].…”

Phase information revealed by interferences in the ionization of rotational wave packets

“…The present theoretical study is based on the usual three-step photoionization scheme used in most recent experiments [12,13], as shown in Figure 1.…”

“…In this article, we show that in a molecular system quantum interferences can be used in combination with electron-nuclear entanglement to extract classical information initially stored in a rotational wave packet. This approach is inspired by a set of beautiful experiments performed on Rydberg atom data registers [10,11], and on Li 2 in the context of femtochemistry [12] and for coherent control [13,14]. This * Electronic address: Eric.Charron@ppm.u-psud.fr † Electronic address: Maurice.Raoult@lac.u-psud.fr last system has also been used for the implementation of various simple quantum algorithms [15].…”