scholarly journals Phononic Josephson oscillation and self-trapping with two-phonon exchange interaction

2017 ◽  
Vol 96 (2) ◽  
Author(s):  
Xun-Wei Xu ◽  
Ai-Xi Chen ◽  
Yu-xi Liu
2012 ◽  
Vol 23 (11) ◽  
pp. 1250076 ◽  
Author(s):  
WEN-YUAN WANG ◽  
WEN-SHAN DUAN ◽  
JIE LIU

By considering the contribution of the higher-order term representing the lowest approximation of beyond mean field corrections, we investigate a superfluid Fermi gas confined in a double-well potential in Bose–Einstein Condensation (BEC) side of the Bardeen–Cooper–Schrieffer (BCS) to BEC crossover. Two limited cases of deep BEC regime and BEC regime of BCS–BEC crossover, corresponding to the two-body scattering length a sc is small enough and large enough, respectively. We derive a simple two-mode model that could depict the dynamics effectively. With making thorough analysis on the two-mode model and its corresponding classical Hamiltonian, we find that the Josephson oscillation or self-trapping phenomenon could emerge at certain parameters. We find three kinds of the phase states: Josephson oscillation (JO), oscillating-phase-type self-trapping (OPTST) and running-phase-type self-trapping (RPTST). The dependence of these three phase states on the dimensionless interaction parameter y = 1/(kFa sc ) and the initial system energy are given in this paper.


2018 ◽  
Vol 97 (4) ◽  
Author(s):  
Yi Zheng ◽  
Shiping Feng ◽  
Shi-Jie Yang

1980 ◽  
Vol 41 (C5) ◽  
pp. C5-289-C5-292 ◽  
Author(s):  
C. Lewiner ◽  
J. A. Gaj ◽  
G. Bastard

Author(s):  
О. Мирославович Карбованець ◽  
Мирослав Іванович Карбованець ◽  
Володимир Юрійович Лазур ◽  
М. В. Хома

2016 ◽  
pp. 4024-4028 ◽  
Author(s):  
Sergey I. Pokutnyi ◽  
Wlodzimierz Salejda

The possibility of occurrence of the excitonic  quasimolecule formed of spatially separated electrons and holes in a nanosystem that consists  of  CuO quantum dots synthesized in a silicate glass matrix. It is shown that the major contribution to the excitonic quasimolecule binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes.


2020 ◽  
Author(s):  
wenda wu ◽  
Jian Luo ◽  
Fang Wang ◽  
Bing Yuan ◽  
Tianbiao Liu

Aqueous organic redox flow batteries (AORFBs) have become increasing attractive for scalable energy storage. However, it remains challenging to develop high voltage, powerful AORFBs because of the lack of catholytes with high redox potential. Herein, we report methyl viologen dibromide (<b>[MV]Br<sub>2</sub></b>) as a facile self-trapping, bipolar redox electrolyte material for pH neutral redox flow battery applications. The formation of the <b>[MV](Br<sub>3</sub>)<sub>2</sub></b> complex was computationally predicted and experimentally confirmed. The low solubility <b>[MV](Br<sub>3</sub>)<sub>2</sub></b> complex in the catholyte during the battery charge process not only mitigates the crossover of charged tribromide species (Br<sub>3</sub><sup>-</sup>) and addresses the toxicity concern of volatile bromine simultaneously. A 1.53 V bipolar MV/Br AORFB delivered outstanding battery performance at pH neutral conditions, specifically, 100% total capacity retention, 133 mW/cm<sup>2</sup> power density, and 60% energy efficiency at 40 mA/cm<sup>2</sup>.


Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 87-95
Author(s):  
M. S. Baranava ◽  
P. A. Praskurava

The search for fundamental physical laws which lead to stable high-temperature ferromagnetism is an urgent task. In addition to the already synthesized two-dimensional materials, there remains a wide list of possible structures, the stability of which is predicted theoretically. The article suggests the results of studying the electronic properties of MAX3 (M = Cr, Fe, A = Ge, Si, X = S, Se, Te) transition metals based compounds with nanostructured magnetism. The research was carried out using quantum mechanical simulation in specialized VASP software and calculations within the Heisenberg model. The ground magnetic states of twodimensional MAX3 and the corresponding energy band structures are determined. We found that among the systems under study, CrGeTe3 is a semiconductor nanosized ferromagnet. In addition, one is a semiconductor with a bandgap of 0.35 eV. Other materials are antiferromagnetic. The magnetic moment in MAX3 is localized on the transition metal atoms: in particular, the main one on the d-orbital of the transition metal atom (and only a small part on the p-orbital of the chalcogen). For CrGeTe3, the exchange interaction integral is calculated. The mechanisms of the formation of magnetic order was established. According to the obtained exchange interaction integrals, a strong ferromagnetic order is formed in the semiconductor plane. The distribution of the projection density of electronic states indicates hybridization between the d-orbital of the transition metal atom and the p-orbital of the chalcogen. The study revealed that the exchange interaction by the mechanism of superexchange is more probabilistic.


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