40 research outputs found
Optimal use of time dependent probability density data to extract potential energy surfaces
A novel algorithm was recently presented to utilize emerging time dependent
probability density data to extract molecular potential energy surfaces. This
paper builds on the previous work and seeks to enhance the capabilities of the
extraction algorithm: An improved method of removing the generally ill-posed
nature of the inverse problem is introduced via an extended Tikhonov
regularization and methods for choosing the optimal regularization parameters
are discussed. Several ways to incorporate multiple data sets are investigated,
including the means to optimally combine data from many experiments exploring
different portions of the potential. Results are presented on the stability of
the inversion procedure, including the optimal combination scheme, under the
influence of data noise. The method is applied to the simulated inversion of a
double well system.Comment: 34 pages, 5 figures, LaTeX with REVTeX and Graphicx-Package;
submitted to PhysRevA; several descriptions and explanations extended in Sec.
I
Monotonic Convergent Optimal Control Theory with Strict Limitations on the Spectrum of Optimized Laser Fields
A New Mechanism for Photosynthetic Energy Transfer
Calculations reveal a new kind of non-adiabatic funnel that electronically enhances anti-correlated vibrational wavepackets on the ground state. These wavepackets replicate all observed 2D signatures of photosynthetic energy transfer, including one not previously explained
Ballistic energy transport in PEG oligomers
Energy transport between the terminal groups of the azido-PEG-succinimide ester compounds with a number of repeating PEG units of 0, 4, 8, and 12 was studied using relaxation-assisted two-dimensional infrared spectroscopy. The through-bond energy transport time, evaluated as the waiting time at which the cross peak maximum is reached, Tmax, was found to be linearly dependent on the chain length for chain lengths up to 60 Å suggesting a ballistic energy transport regime. The through-bond energy transport speed is found to be ca. 500 m/s. The cross-peak amplitude at the maximum decays exponentially with the chain length with a characteristic decay distance of 15.7 ± 1 Å. Substantial mode delocalization across the PEG bridge is found, which can support the energy propagation as a wavepacket
Ultrafast optical manipulation of atomic motion in multilayer Ge-Sb-Te phase change materials
Ultrafast nonlinear dynamics in thin GaN films studied by femtosecond digital holography
We studied the nonlinear propagation dynamics of intense 300 fs infrared pulses in thin GaN films by use of pulsed digital holography technique with 25 fs temporal resolution