SU(3) trimer resonating-valence-bond state on the square lattice

We propose and study an SU(3) trimer resonating-valence-bond (tRVB) state with $C_{4v}$ point-group symmetry on the square lattice. By devising a projected entangled-pair state representation, we show that all (connected) correlation functions between local operators in this SU(3) tRVB state decay exponentially, indicating its gapped nature. We further calculate the modular $S$ and $T$ matrices by constructing all nine topological sectors on a torus and establish the existence of $\mathbb{Z}_3$ topological order in this SU(3) tRVB state.Comment: 6 pages, 6 figure

Poly[(μ3-5-bromo­nicotinato)(5-bromo­nicotinato)copper(II)]

The title coordination polymer, [Cu(C6H3BrNO2)2]n, is composed of two structurally similar two-dimensional coordination polymers (twin layers). Both of them have the same chemical composition but they display different bond lengths and angles. In each layer, two N atoms and four carboxyl­ate O atoms from the bridging 5-bromo­nicotinate ligands and four carboxyl­ate O atoms from the terminal 5-bromo­nicotinate ligands bind to two CuII atoms to form a dinuclear paddle-wheel-like pattern. Adjacent paddle wheels are further linked by bridging 5-bromo­nicotinate groups to generate a two-dimensional coordination polymer; neighboring twin-like layers are finally stacked through π–π stacking interactions between adjacent pyridine rings [perpendicular distance of 3.626 (2) Å] in a ‘sandwich’ manner, thus generating a three-dimensional supra­molecular structure

Efficient Volumetric Method of Moments for Modeling Plasmonic Thin-Film Solar Cells with Periodic Structures

Metallic nanoparticles (NPs) support localized surface plasmon resonances (LSPRs), which enable to concentrate sunlight at the active layer of solar cells. However, full-wave modeling of the plasmonic solar cells faces great challenges in terms of huge computational workload and bad matrix condition. It is tremendously difficult to accurately and efficiently simulate near-field multiple scattering effects from plasmonic NPs embedded into solar cells. In this work, a preconditioned volume integral equation (VIE) is proposed to model plasmonic organic solar cells (OSCs). The diagonal block preconditioner is applied to different material domains of the device structure. As a result, better convergence and higher computing efficiency are achieved. Moreover, the calculation is further accelerated by two-dimensional periodic Green's functions. Using the proposed method, the dependences of optical absorption on the wavelengths and incident angles are investigated. Angular responses of the plasmonic OSCs show the super-Lambertian absorption on the plasmon resonance but near-Lambertian absorption off the plasmon resonance. The volumetric method of moments and explored physical understanding are of great help to investigate the optical responses of OSCs.Comment: 11 pages, 6 figure