The Harmonic Potential Theorem for a Quantum System with Time-Dependent Effective Mass

We investigate the many-body wave function of a quantum system with time-dependent effective mass, confined by a harmonic potential with time-dependent frequency, and perturbed by a time-dependent spatially homogeneous electric field. It is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schr6dinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the harmonic potential theorem wave function when both the effective mass and frequency are static. An example of application is also given.

Crystal Structure and Properties of a Sodium Terbium Borate Na_(2.67)Tb_(2.11)B_3O_9

A new nonlinear optical crystal of sodium terbium borate （Na2.67Tb2.11B3O9, Mr = 573.14） was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was deter- mined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a = 5.0744（10）, b = 10.990（2）, c = 6.9078（14） A, V = 385.24（13） A3, Dc = 4.941 g/cm3, F（000） = 250, Z = 2, μ= 9.205 mm-1, the final R = 0.0253 and wR = 0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na（1）O8, Na（2）O6, Na（3）O6 and Tb（1）O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic （μj = 7.04 μb）. The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.

Synthesis of Two-Color Laser Pulses for the Harmonic Cutoff Extension

Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation(HHG).For this purpose,the shaping of the waveform of driving pulse is an alternative approach.Here,we show that the harmonic cutoff can be extended by about two times without reducing harmonic yield after considering macroscopic propagation effects,by adopting a practical way to synthesize two-color fields with fixed energy.Our results,combined with the experimental techniques,show the great potential of HHG as a tabletop light source.

Effect of acidity on morphologies and photodimerization kinetics in Langmuir-Blodgett monolayers of styrylquinoline derivatives

The real-time second harmonic generation was employed to investigate the[2＋2]photodimerization of styrylquinoline（SQ） derivatives in Langmuir-Blodgett（LB） monolayers deposited from aqueous subphases with different acidity.It was discovered that the photodimerization rate constant significantly decreased upon the addition of acid.The additional atomic force microscopy measurements revealed that surface morphologies were correlated to the photodimerization kinetics.These experimental results provide direct evidence for the topo-chemical mechanisms of[2＋2]photodimerization in LB films.The current study demonstrates that the intermolecular interactions and aggregation structures play important roles in the photochemical properties at surfaces.