An adiabatic local model for the internal structure of charge-transfer excitons: Dimers and trimers

In charge-transfer crystals, the exciton-phonon interaction significantly influences the internal structure of charge-transfer excitons (CTEs). The formation of CTE dimers and trimers is considered in an adiabatic non-centrosymmetric model which includes phonon dispersion. Changes of lattice frequencies near the CTE are analysed.     

A Low-Frequency Photoacoustic Spectrometer with an RGB Light-Emitting Diode for Evaluating Photosynthetic Activity in Plant Leaves

Acoustical Physics - A photoacoustic spectrometer based on a three-colored light-emitting diode (with peak emission wavelengths of 465, 525, and 640 nm) designed to determine the intensity of...     

Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

Diamond direct and inverse opal matrices produced by chemical vapor deposition

Diamond structures with inverse and direct three-dimensional opal lattices with period of 250–530 nm were grown by microwave plasma deposition in methane-hydrogen mixtures using porous SiO₂ opal matrix and its Si replica as templates, respectively. The Si templates can be filled with diamond to the depth as large as 80 layers of the spheres.     

Aspect-ratio dependent oscillatory thermocapillary convection in the floating half zone

The dependency of the critical Marangoni number on the geometrical aspect ratio of the floating half zone is essential to predict the onset of oscillatory thermocapillary convection.The experimental studies in the microgravity conditions on floating half zones of several centimeters in diameter have predicted that the critical Marangoni number increases with the increasing aspect ratio,and the terrestrial experimental studies have predicted the contradictory conclusion for floating half zones of several mil...