Note on Triangle Anomalies and Assignment of Singlet in 331-like Model

It is pointed out that in the $331-$like model which uses both fundamental and complex conjugate representations for an assignment of the representations to the left-handed quarks and the scalar representation to their corresponding right-handed counterparts, the nature of the scalar should be taken into account in order to make the fermion triangle anomalies in the theory anomaly-free, i.e. renormalizable in a sense with no anomalies, even after the spontaneous symmetry breaking.Comment: 8 page no figures, acknowledgments adde

Physical IC debug ─ backside approach and nanoscale challenge

Physical analysis for IC functionality in submicron technologies requires access through chip backside. Based upon typical global backside preparation with 50–100 µm moderate silicon thickness remaining, a state of the art of the analysis techniques available for this purpose is presented and evaluated for functional analysis and layout pattern resolution potential. A circuit edit technique valid for nano technology ICs, is also presented that is based upon the formation of local trenches using the bottom of Shallow Trench Isolation (STI) as endpoint for Focused Ion Beam (FIB) milling. As a derivative from this process, a locally ultra thin silicon device can be processed, creating a back surface as work bench for breakthrough applications of nanoscale analysis techniques to a fully functional circuit through chip backside. Several applications demonstrate the power and potential of this new approach

High-speed two-photon polymerization 3D printing with a microchip laser at its fundamental wavelength

High-resolution, high-speed 3D printing by two-photon polymerization (2PP) with a Nd:YVO4 Q-switched microchip laser at its fundamental wavelength of 1064 nm is demonstrated. Polymerization scan speeds of up to 20 mm/s and feature sizes of 250 nm are achieved using a high repetition rate Q-switched microchip laser with a semiconductor saturable absorber mirror (SESAM) and photoresist with a new photo-initiator bearing 6-dialkylaminobenzufuran as electron donor and indene-1,3-dione moiety as electron acceptor. The obtained results demonstrate the high potential of Q-switched microchip lasers for applications in 2PP 3D printing

Injection Kinetics and Electronic Structure at the N719 TiO2 Interface Studied by Means of Ultrafast XUV Photoemission Spectroscopy

The method of transient XUV photoemission spectroscopy is developed to investigate the ultrafast dynamics of heterogeneous electron transfer at the interface between the N719 ruthenium dye complex and TiO2 nanoparticles. XUV light from high order harmonic generation is used to probe the electron density distribution among the ground and excited states at the interface after its exposure to a pump laser pulse of 530 nm wavelength. A spectral decomposition of the transient emission signal is used to follow the population and decay dynamics of the involved transient states individually. By comparing results obtained for the N719 TiO2 and N719 FTO interfaces, we can unambiguously reveal the kinetics of electrons injected to TiO2 from the singlet metal to ligand charge transfer MLCT excited state of the dye. With the developed approach, we characterize both the kinetic constants and the absolute binding energies of the singlet and triplet MLCT states of the dye and the state of electrons injected to the conduction band of TiO2. The energy levels of the singlet and triplet states are found to lie 0.7 eV above and 0.2 eV below the conduction band minimum, respectively. This energetic structure gives rise to a strong driving force for injection from the singlet state and a slow electron transfer from the triplet state, the latter being possible due to a partial overlap of the triplet state band of N719 and the conduction band of TiO

Electron affinity of Li: A state-selective measurement

We have investigated the threshold of photodetachment of Li^- leading to the formation of the residual Li atom in the $2p ^2P$ state. The excited residual atom was selectively photoionized via an intermediate Rydberg state and the resulting Li^+ ion was detected. A collinear laser-ion beam geometry enabled both high resolution and sensitivity to be attained. We have demonstrated the potential of this state selective photodetachment spectroscopic method by improving the accuracy of Li electron affinity measurements an order of magnitude. From a fit to the Wigner law in the threshold region, we obtained a Li electron affinity of 0.618 049(20) eV.Comment: 5 pages,6 figures,22 reference

Photodetachment study of the 1s3s4s ^4S resonance in He^-

A Feshbach resonance associated with the 1s3s4s ^{4}S state of He^{-} has been observed in the He(1s2s ^{3}S) + e^- (\epsilon s) partial photodetachment cross section. The residual He(1s2s ^{3}S) atoms were resonantly ionized and the resulting He^+ ions were detected in the presence of a small background. A collinear laser-ion beam apparatus was used to attain both high resolution and sensitivity. We measured a resonance energy E_r = 2.959 255(7) eV and a width \Gamma = 0.19(3) meV, in agreement with a recent calculation.Comment: LaTeX article, 4 pages, 3 figures, 21 reference

Multiscale Photon Based In Situ and Operando Spectroscopies in Time and Energy Landscapes

Following catalytic reactions, in situ and operando are now the focus of a number of dedicated experiments at light sources which have been developed to track the electronic and molecular structural dynamics of catalysts. The challenges for this goal are two fold first, the development of spectroscopic tools in the energy domain and time domain is required. The photocatalytic processes have early dynamics of tens of femtoseconds, while further reaction takes seconds, minutes, and even hours. Second, a combination of tools to probe processes not only in solids, but also in solutions and at interfaces, is now needed. In this special issue, we present recent developments at the synchrotron facility BESSY II using photon energy from the infrared and extreme ultraviolet up to the soft X ray regime for in situ and operando applications addressing these two major challenges. As this work is a result of contributions from several groups, each section will present the group s activities and related team members involve

Synthesis of periodic plasmonic microstructures with copper nanoparticles in silica glass by low-energy ion implantation

Ion implantation was used to locally modify the surface of silica glass to create periodic plasmonic microstructures with Cu nanoparticles. Nanoparticles were synthesized by Cu-ion irradiation of the silica glass at the ion energy of 40 keV, dose of 5×1016 ions/cm2 and current density of 5 μA/cm2. This procedure involves low-energy ion implantation into the glass through a mask placed at the surface. Formation of nanoparticles was observed by optical spectroscopy and atomic force microscopy. The presented results clearly demonstrate how the low-energy ions can be used for the fabrication of photonic microstructures on dielectric surfaces in a single-step process. © 2012 Springer-Verlag Berlin Heidelberg