On Binding Energy of Trions in Bulk Materials

We study the negatively $T^{-}$ and positively $T^{+}$ charged trions in bulk materials in the effective mass approximation within the framework of a potential model. The binding energies of trions in various semiconductors are calculated by employing Faddeev equation in configuration space. Results of calculations of the binding energies for $T^{-}$ are consistent with previous computational studies and are in reasonable agreement with experimental measurements, while the $T^{+}$ is unbound for all considered cases. The mechanism of formation of the binding energy of trions is analysed by comparing contributions of a mass-polarization term related to kinetic energy operators and a term related to the Coulomb repulsion of identical particles.Comment: 7 pages, 4 figure

Disappearance of Quantum Chaos in Coupled Chaotic Quantum Dots

Statistical properties of the single electron levels confined in the semiconductor (InAs/GaAs, Si/SiO2) double quantum dots (DQDs) are considered. We demonstrate that in the electronically coupled chaotic quantum dots the chaos with its level repulsion disappears and the nearest neighbor level statistics becomes Poissonian. This result is discussed in the light of the recently predicted "huge conductance peak" by R.S. Whitney at al. (Phys. Rev. Lett. {\bf 102}, 186802 (2009)) in the mirror symmetric DQDs.Comment: 4 pages, 9 figure

Computer Code for Nanostructure Simulation

Due to their small size, nanostructures can have stress and thermal gradients that are larger than any macroscopic analogue. These gradients can lead to specific regions that are susceptible to failure via processes such as plastic deformation by dislocation emission, chemical debonding, and interfacial alloying. A program has been developed that rigorously simulates and predicts optoelectronic properties of nanostructures of virtually any geometrical complexity and material composition. It can be used in simulations of energy level structure, wave functions, density of states of spatially configured phonon-coupled electrons, excitons in quantum dots, quantum rings, quantum ring complexes, and more. The code can be used to calculate stress distributions and thermal transport properties for a variety of nanostructures and interfaces, transport and scattering at nanoscale interfaces and surfaces under various stress states, and alloy compositional gradients. The code allows users to perform modeling of charge transport processes through quantum-dot (QD) arrays as functions of inter-dot distance, array order versus disorder, QD orientation, shape, size, and chemical composition for applications in photovoltaics and physical properties of QD-based biochemical sensors. The code can be used to study the hot exciton formation/relation dynamics in arrays of QDs of different shapes and sizes at different temperatures. It also can be used to understand the relation among the deposition parameters and inherent stresses, strain deformation, heat flow, and failure of nanostructures

Nakupinski račun 9ΛBe hiperjezgre Faddeevom metodom

Configuration-space Faddeev calculations are performed for cluster model ααΛ of the 9 ΛBe hypernucleus using various αΛ potentials. For the αα interaction, the nuclear component is only taken into account (phenomenological Ali-Bodmer potential). The binding energy of the 9 ΛBe hypernuclei is calculated for two different potential models. In the first model, the s-wave αΛ potential acting in all partial waves in the αΛ subsystem is used. In the second model, a recent more realistic αΛ potential having the s- and p-partial components is employed. The core effect of nuclear αα potential is also studied.Načinili smo račune Faddeevom metodom u konfiguracijskom prostoru za nakupinski model ααΛ hiperjezgre 9 ΛBe primjenom različitih potencijala. Za nuklearnu sastavnicu međudjelovanja αα primijenili smo samo fenomenološki Ali-Bodmerov potencijal. Energiju vezanja hiperjezgre 9 ΛBe smo računali dvama različitim potencijalnim modelima. U prvome se rabi s-valni potencijal αΛ koji djeluje na sve parcijalne valove u podsustavu αΛ. U drugome, rabi se nov realističniji potencijal αΛ koji sadrži s- i p-parcijalne sastavnice. Proučavali smo također učinak sredice u potencijalu αα

The charge and mass symmetry breaking in the KKKˉKK\bar{K} system

In the framework of the Faddeev equations in configuration space, we investigate the $K$(1460) meson as a resonant state of the $KK\bar{K}$ kaonic system. We perform calculations for the particle configurations $K^{0}K^{+}K^{-}$ and $K^{0}K^{+}\overline{{K}^{0}}$ within two models: the $ABC$ model, in which all three particles are distinguishable, and the $AAC$ model when two particles are identical. The models differ in their treatment of the kaon mass difference and the attractive Coulomb force between the $K^{+}K^{-}$ pair. We found that the Coulomb shift adds over 1 MeV to the three-body binding energy. The expected correction to the binding energy due to mass redistribution from $AA$ to $AB$ is found to be negligible, up to a maximum of 6\% of the relative mass correction. At the same time, the symmetry of the wave function is distorted depending on the mass ratio value. We found that the repulsive $KK$ interaction plays essential role in the binding energy of the $KK\bar K$ system and report the mass of 1461.8 or 1464.1 MeV for the neutral $K^{0}$(1460) and 1466.5 or 1468.8 MeV for the charged $K^{+}$(1460) resonances, respectively, depending on the parameter sets for $KK$ and $K\bar{K}$ interactions.Comment: 13 page, 4 figure

Kpp and KKp Clusters

The three-body kaonic Kpp and KKp clusters are studied using the method of hyperspherical harmonics (HH) in momentum representation and differential Faddeev equations (DFE). We use different NN and KN interactions. Results obtained by the methods of HH and DFE are in reasonable agreement. The binding energy and the width show very strong dependence on the KN potential. We have two different classes of results: the results based on phenomenological strong KN potential, and the results obtained with much weaker chiral SU(3)-based KN potential

Effect of isospin averaging for ppK−ppK^- kaonic cluster

The kaonic cluster ppK^-ppK− is described by isospin-dependent N{\bar K}NK‾ potentials with significant difference between singlet and triplet components. The quasi-bound state energy of the system is calculated based on the configuration space Faddeev equations within isospin and averaged potential models. The isospin averaging of N{\bar K}NK‾ potentials is used to simplify the isospin model to isospinless one. We show that three-body bound state energy E_{3}E3 has a lower bound within the isospin formalism due to relation \left\vert E_{3}(V_{NN}=0)\right\vert&lt;2\left\vert E_{2}\right\vert|E3(VNN=0)|&lt;2|E2|, where E_{2}E2 is the binding energy of isospin singlet state of the N{\bar K}NK‾ subsystem. The averaged potential model demonstrates opposite relation between |E_{2}||E2| and |E_{3}(V_{NN}=0)||E3(VNN=0)|.</jats:p