A systematic optical study, including micro, ensemble and time resolved photoluminescence of GaAs/AlGaAs triple concentric quantum rings, self-assembled via droplet epitaxy, is presented. Clear emission from localized states belonging to the ring structures is reported. The triple rings show a fast decay dynamics, around 40 ps, which is expected to be useful for ultrafast optical switching appl...

Abstract We calculate photon sphere and critical curve $b_c$?> for a quantum corrected Schwarzschild black hole, finding that they violate universal inequalities proved asymptotically flat holes satisfy the null energy condition in framework of Einstein gravity. This violation seems to be common phenomenon when considering modification Furthermore, we study shadows, lensing r...

A novel feature for control of carrier mobility is explored in an order-disorder separated double quantum ring, where the two rings thread different magnetic fluxes. Here we use simple tight-binding formulation to describe the system. In our model, the two rings are connected through a single bond and one of the rings is subjected to impurity, keeping the other ring as impurity free. In the str...

Abstract Many well-known local rings, including soluble Iwasawa algebras and certain completed quantum algebras, arise naturally as iterated skew power series rings. We calculate their Krull global dimensions, obtaining lower bounds to complement the upper obtained by Wang. In fact, we show that many common such rings obey a stronger property, which call triangularity, allows us also classical ...

We demonstrate the self-assembled formation of concentric quantum double rings with high uniformity and excellent rotational symmetry using the droplet epitaxy technique. Varying the growth process conditions can control each ring's size. Photoluminescence spectra emitted from an individual quantum ring complex show peculiar quantized levels that are specified by the carriers' orbital trajector...

In this paper a comparative theoretical study was made of the magneto-optical response of square lattices of nanoobjects dots and rings . Expressions for both the polarizability of the individual objects as their mutual electromagnetic interactions for a lattice in vacuum was derived. The quantum-mechanical part of the derivation is based upon the commonly used envelope function approximation. ...

L. Viola1,2∗, R. Onofrio1† and T. Calarco3‡ 1 Dipartimento di Fisica “G. Galilei”, Università di Padova, and INFN, Sezione di Padova, Via Marzolo 8, Padova, Italy 35131 2 Department of Physics, Massachusetts Institute of Technology, 12-127, 77 Massachusetts Ave., Cambridge, MA 02139 3 Dipartimento di Fisica, Università di Ferrara, and INFN, Sezione di Ferrara, Via Paradiso 12, Ferrara, Italy 44...

In this research at the first complex and its halogenated derivatives were optimized. NBO calculations and NMR for the complexes were carried out at the B3LYP/6-31G*quantum chemistry level. In the 1- (4-fluorophenyl) -2, 3-dihydro-1 H-naphto- [1, 2-e] [1, 3] oxazine-3-n, there are 4 rings, respectively, rings from the side attached to the halogen They are named C, B, A, and D. Calculations and ...

We investigate the difference in the response of a one-dimensional semiconductor quantum ring and a finite-width ring to a strong and short-lived time-dependent perturbation in the THz regime. In both cases the persistent current is modified through a nonadiabatic change of the many-electron states of the system, but by different mechanisms in each case. PACS numbers: 73.23.Ra, 75.75.+a