The quantum–classical transition of wave packet barrier scattering is investigated using a hydrodynamic description in the framework of a nonlinear Schrödinger equation. The nonlinear equation ...provides a continuous description for the quantum–classical transition of physical systems by introducing a degree of quantumness. Based on the transition equation, the transition trajectory formalism is developed to establish the connection between classical and quantum trajectories. The quantum–classical transition is then analyzed for the scattering of a Gaussian wave packet from an Eckart barrier and the decay of a metastable state. Computational results for the evolution of the wave packet and the transmission probabilities indicate that classical results are recovered when the degree of quantumness tends to zero. Classical trajectories are in excellent agreement with the transition trajectories in the classical limit, except in some regions where transition trajectories cannot cross because of the single-valuedness of the transition wave function. As the computational results demonstrate, the process that the Planck constant tends to zero is equivalent to the gradual removal of quantum effects originating from the quantum potential. This study provides an insightful trajectory interpretation for the quantum–classical transition of wave packet barrier scattering.
We introduce a computationally efficient continuum technique to simulate the complex kinetic pathways of block copolymer self-assembly. Subdiffusive chain dynamics is taken into account via nonlocal ...Onsager coefficients. An application to directed self-assembly of thin films of diblock copolymers on patterned substrates reveals the conditions under which experimentally observed metastable structures intervene in the desired thin-film morphology. The approach generalizes easily to multiblock copolymers and more complex guiding patterns on the substrate, and its efficiency allows for the systematic optimization of guiding patterns and process conditions.
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•Photoinduced NO-linkage isomers were investigated in K2RuF5NO.H2O (RuFNO).•Samples of RuFNO at 77 K were irradiated with laser light in a 260–1064 nm range.•The photoisomer generated ...by light were evidenced by IR spectroscopy.•A novel method to explore the electronic structure of RuF5NO2- ion is proposed.•The onset decay temperature for the MS1 photoisomer is about 180 K.
Some mononitrosyl complexes of transition metals exhibit one or two metastable states (linkage isomers, MS1 and MS2) when irradiated at low temperatures with appropriate wavelengths. In this work, the generation of metastable state one (MS1) (or Ru-ON linkage isomer) in K2RuF5NO.H2O at 77 K was studied by sample excitation using laser light in a wide range of wavelengths. The effects of irradiation was monitored by infrared spectroscopy. ν(NO) in the ground state was shifted by −161 cm−1 when the complex was excited to MS1, a magnitude similar to that observed in other transition metal nitrosyls for a such state. We report on the excitation and deactivation of metastable states by using a wide variety of laser lines. A novel method for exploring the electronic structure of RuF5NO2- through the generation of MS1 is proposed. For this purpose, a sample was carefully irradiated with the same intensity of light for all laser lines in the spectral region 260–1064 nm. The integrated area under the ν(NO)MS1 band was used as a measure of MS1 population. The profile peaks of the MS1 population (ν(NO)MS1 band area) vs. the irradiation wavelength fit well with those of the electronic spectrum of the RuF5NO2- ion in an aqueous solution. The onset temperature for MS1 decay in K2RuF5NO.H2O, at approximately 180 K, is slightly lower than the average reported for other ruthenium-nitrosyl systems.
Nanostructures with rich physical properties are promising for applications in electronics, chemistry, energy and bioscience, etc. The relationship and manipulation among different nanostructures as ...a hot topic attract many attentions. However, the transformation, such as nucleation events and metastable states, is rarely observed. The electron beam‐induced perturbations of the system can be used to manipulate nanostructures by controlling the properties of the focused electron beam. Here, taking advantage of an electron beam to induce the direct growth of bismuth (Bi) nanodroplets on the Bi nanowire, the transformation between nucleation and decomposition processes within the nanoparticles is studied by high‐resolution transmission electron microscopy (HRTEM). The results show that the nucleation occurred at the edge of the Bi nanodroplet, and the metastable state in coalesced area introduced the additional interfacial states, determining the nucleation and decomposition of the nanostructure. This study helps to observe the critical process, reduce the gap between theory and experiment for reducing interfacial area to improve the energy storage efficiency.
The reversible phase transition of bismuth on Bi nanowire is manipulated by e‐beam irradiation in a transmission electron microscope. Taking advantage of an electron beam to induce the direct growth of Bi nanodroplets on the Bi nanowire, the transformation between solidification and liquidation processes within the nanoparticles is studied by high‐resolution transmission electron microscopy (HRTEM). The results show that the metastable state in coalesced area introduced additional interfacial states, determining the solidification and liquidation of the nanostructure.
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