Attosecond regime

Of course, even when the world s fastest laser pulses are available, there is always a feehng that what is really required is pulses that are faster still Laser pulses with durations in the attosecond regime would open up the possibility of observing the motions of electrons in atoms and molecules on their natural time scale and would enable phenomena such as atomic and molecular ionisation (Section 1.2) and the dynamics of electron orbits about nuclei to be captured in real time. 

This simple statistical model is compatible, for the case of neon, with the data available thus far. Moreover, it allows one to infer a value of the thermalization time. This value comes out to be in the attosecond regime. In principle, such bounds can be made even tighter by reducing the widths of the electron-momentum distributions. This can be done by limiting the temporal range of return times for the first electron using, for instance, an additional perpendicularly polarized driving wave at twice the frequency. 

Because electrons are much lighter than nuclei, they move much faster. The intrinsic temporal regime for valence bond electron dynamics is the few femtosecond to several hundred attosecond timescale. Therefore, efficient and accurate control of electron dynamics requires extreme precision regarding the control field. Commonly attosecond techniques are considered to be the appropriate tools for efficient manipulation of electron motions [61-63, 111, 112]. However, attosecond pulses in the XUV region are not suited for efficient valence bond excitation (see Section 6.1). Here we demonstrate that ultrafast electron dynamics are controlled efficiently on the sub-10 as timescale employing a pair of femtosecond laser pulses with a temporal separation controllable down to zeptosecond precision [8]. 

I. P. Christov, N.H. Murnane, H.C. Kapteyii High-harmonic generation of attosecond pulses in the single-cycle regime. Phys. Rev. Lett. 78, 1251 (1997)... 

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