We investigate gallium and nitrogen vacancies in gallium nitride (GaN) bulk and nanowires using self-interaction corrected pseudopotentials (SIC). In particular, we examine the band structures to compare and contrast differences between the SIC results and standard density functional theory (DFT) results using a generalized gradient approximation (GGA) (Perdew et al 1996 Phys. Rev. Lett. 77 386...

The effect of the Zeeman field on the defect-induced Kondo effect in graphene is investigated. The effective model of the Kondo effect is derived, and is analyzed on the basis of the numerical renormalization group method. It is found that, under the Zeeman field, at the border of the spin polarized state and the Kondo-Yosida singlet state, there is an unusual fixed point where the entropy of t...

Photon interference among distant quantum emitters is a promising method to generate large scale quantum networks. Interference is best achieved when photons show long coherence times. For the nitrogen-vacancy defect center in diamond we measure the coherence times of photons via optically induced Rabi oscillations. Experiments reveal a close to Fourier-transform (i.e., lifetime) limited width ...

We introduce and analyze a new type of high-Q microcavity consisting of a channel waveguide and a one-dimensional photonic crystal. A band gap for the guided modes is opened and a sharp resonant state is created by adding a single defect in the periodic system. An analysis of the eigenstates shows that strong field confinement of the defect state can be achieved with a modal volume less than ha...

We have investigated native defects and native defect-impurity complexes as candidate sources for the yellow luminescence in GaN. Using state-of-the-art first-principles calculations, we find strong evidence that the Ga vacancy (VGa) is responsible. The dependence of the VGa formation energy on Fermi level explains why the yellow luminescence is observed only in n-type GaN. The VGa defect level...

We study the evolution of entanglement after a global quench in one-dimensional quantum system with localized impurity. For systems described by conformal field theory, entropy between two regions separated defect grows linearly time. Introducing notion boundary twist fields, we show how slope this growth can be related to effective central charge that emerges ground-state presence defect. On o...

option of defect is one of common options between sale and rent contracts, however, it has special rules and conditions in those contracts. in the sale contracts, any defect in the sold or bought thing causes the victim has option of defect but in the rent contracts, only the defect creates option of defect that causes hardship in using of goods or reducing of benefits. in the sale, defect of s...

Defect depth profiles of Cu (In1-x,Gax)(Se1-ySy)2 (CIGSS) were measured as functions of pulse width and voltage via deep-level transient spectroscopy (DLTS). Four defects were observed, i.e., electron traps of ~0.2 eV at 140 K (E1 trap) and 0.47 eV at 300 K (E2 trap) and hole traps of ~0.1 eV at 100 K (H1 trap) and ~0.4 eV at 250 K (H2 trap). The open circuit voltage (VOC) deteriorated when the...

This paper investigates the evolution of defects in two-dimensional (2D) wet foams by using the dynamic bubble simulation approach. Two defect types are considered: a single large bubble, and a cluster of small bubbles inserted in an otherwise monodisperse hexagonal lattice. In the case of a single large defect bubble, the disorder of the cluster associated with the defect is seen to increase a...

Non-radiative recombination plays an important role in the performance of optoelectronic semiconductor devices such as solar cells and light-emitting diodes. Most textbook examples assume that the recombination process occurs through a single defect level, where one electron and one hole are captured and recombined. Based on this simple picture, conventional wisdom is that only defect levels ne...