Laser-induced enhancement of tunneling in NHD2

Abstract

We apply and explore techniques aiming at enhancing the tunneling by laser fields, originally developed for a one-dimensional model, to a complete six-dimensional vibrational model of the inversion motion in NHD(2). The computational study is performed with the multi-configuration time-dependent Hartree method. Assuming an ideal three-dimensional alignment we obtain a driven tunneling time twenty times smaller than the natural one, in rather good agreement with an oversimplified three-state model. In the case of one-dimensional alignment, a linearly polarized field leads to a poor enhancement of the tunneling probability, after averaging over the rotation about the alignment axis, whereas a circularly polarized field improves the rotationally averaged tunneling probability at the end of the pulse.

Atop‐the‐barrier localization in periodically driven double wells: A minimization of information entropic sums in conjugate spaces

“…In the present work, wave packet localization in DWPs, symmetric, asymmetric as well as anharmonic, in the presence of oscillating fields is investigated. Unlike prior work, which is mostly concerned with tunneling and confinement in one of the wells, the present work (for the first time in the literature, to the best of our knowledge) shows localization of the wave packet on the barrier for specific parameters of the linear oscillating field. The time evolution of a bilobal wave packet is presented, where each of the lobes initially indicating a high probability density in each of the wells, merge into a single lobe at the peak rise of the pulse, with localization and stabilization on the barrier.…”

“…Several dynamical aspects of the driven double‐well system have been studied before . The particle‐tunneling time in an SDWP can be reduced with a specific frequency and electric field strength of a laser, leading to tunneling enhancement .…”

“…Several dynamical aspects of the driven double‐well system have been studied before . The particle‐tunneling time in an SDWP can be reduced with a specific frequency and electric field strength of a laser, leading to tunneling enhancement . Coherent destruction of tunneling is an opposite effect, where the tunneling time is increased to an extent such that it does not tunnel through the barrier .…”

The Motion of an Azobenzene Light‐Controlled Switch: A Joint Theoretical and Experimental Approach

“…Even more refined attempts would monitor the molecular dynamics and the time‐dependent molecular structure via the coherent control of amplitudes and phases of the quantum mechanical state describing this structure . One example of this is the laser induced inhibition or enhancement of tunnelling.…”

Theory of Optimizing the Tunneling Probability Through a Potential Barrier by Acoustically Augmented Phonons

“…The conductance of a pair of quantum dots, coupled through a tunnel-barrier and connected to two external leads, exceeds the conductance of the tunnel-barrier-alone tunneling enhancement effect if the device is symmetrical while it strongly decreases if the symmetry is destroyed. Laser-induced enhancement of tunneling in NHD 2 was attempted by Matthieu et al [16]. They found, after averaging over the rotation about the alignment axis, that in the case of one-dimensional alignment, a linearly polarized field leads to a poor enhancement of the tunneling probability, whereas a circularly polarized field improves the rotationally averaged tunnelling probability at the end of the pulse.…”