Thus, in the case of a semiconductor with a parabolic dispersion (for GaAs QD), the dependence of the energy of electron-positron pair on QD sizes is proportional to (r 0 is QD radius), whereas this dependence is

violated in the case of Kane’s Torin 2 in vivo dispersion law (for InSb QD). Moreover, in a spherical QD, accounting of nonparabolicity of dispersion removes the degeneracy of the energy in the orbital quantum number; in a circular QD, in the magnetic quantum number. As it is known, the degeneracy in the orbital quantum number is a result of the hidden symmetry of the Coulomb problem [48]. From this point of view, the lifting of degeneracy is a consequence of lowering symmetry of the problem, which in turn is a consequence of the reduction of the symmetry of the dispersion law of the CC but not a reduction of the geometric symmetry. This results from the narrow-gap semiconductor InSb bands interaction. In other words, with the selection of specific materials, for example,

GaAs or InSb, it is possible to decrease the degree of ‘internal’ symmetry of the sample without changing the external shape, which fundamentally changes the physical properties of the structure. Note also that maintaining twofold degeneracy in the magnetic quantum number www.selleckchem.com/products/etomoxir-na-salt.html in cases of both dispersion laws is a consequence of retaining geometric symmetry. On the other hand, accounting

of nonparabolicity combined with a decrease in the dimensionality of the sample leads to a stronger expression of the sample internal symmetry reduction. Thus, in the 2D case, the energy of Ps atom with Kane’s dispersion law becomes imaginary. In other words, 2D Ps atom in InSb is unstable. The opposite picture is observed in the case of a parabolic dispersion law. In this case, the Ps binding energy increases Amylase up to four times, which in turn should inevitably lead to an increase in a Ps lifetime. It means that it is possible to control the duration of the existence of an electron-positron pair by varying the material, dimension, and SQ. Figure 2 shows the dependences of the ground- and first excited-state energies of the electron-positron pair in a spherical QD on the QD radius in the strong SQ regime. Numerical calculations are made for the QD consisting of InSb with the following parameters: , , E g  ≃ 0.23 eV, κ = 17.8, a p  ≃ 103Å, , and α 0 ≃ 0.123. As it is seen from the figure, at the small values of QD radius, the behavior of curves corresponding to the cases of parabolic and Kane’s dispersion laws selleck chemicals llc significantly differ from each other. The energies of both cases decrease with the increase in QD radius and practically merge as a result of decreasing the SQ influence.