The magnonic band structures for exchange spin waves propagating in one-dimensional magnonic crystal waveguides of different material combinations are investigated using micromagnetic simulations. The waveguides are periodic arrays of alternating nanostripes of different ferromagnetic materials. Our results show that the widths and center frequencies of the bandgaps are controllable by the comp...

It is shown that current saturation in semiconducting carbon nanotubes is indistinguishable from metallic nanotubes if the carrier density is above a critical value determined by the bandgap and the optical phonon energy. This feature stems from the higher number of current-carrying states in the semiconducting tubes due to the van Hove singularity at the band edge. Above this critical carrier ...

The design of bandgap-based voltage references in digital CMOS raises several design difficulties, as the supply voltage is lower than the silicon bandgap in electron volts, i.e., 1.2 V. A current-mode architecture is used in order to address the main issues posed by the low supply, but the implementation of the operational amplifier and of dedicated startup circuits deserves some attention. Ev...

The bandgap of a semiconductor is one of its most important electronic properties. It is often considered to be a fixed property of the semiconductor. As the dimensions of semiconductors reduce, however, many-body effects become dominant. Here, we show that doping and dielectric, two critical features of semiconductor device manufacturing, can dramatically shrink (renormalize) the bandgap. We d...

In this Letter we propose a novel (to our knowledge) porous-core honeycomb bandgap design. The holes of the porous core are the same size as the holes in the surrounding cladding, thereby giving the proposed fiber important manufacturing benefits. The fiber is shown to have a 0.35-THz-wide fundamental bandgap centered at 1.05 THz. The calculated minimum loss of the fiber is 0.25 dB/cm.

We propose a hybrid-guidance photonic crystal fiber (HG-PCF) that can guide light by the simultaneous effect of index guidance and photonic bandgap guidance at all wavelengths and directions. Index guidance is the dominant guidance mechanism at short wavelengths and photonic bandgap guidance is the dominant guidance mechanism at long wavelengths. The transmission spectrum of the Bragg grating i...

This paper presents the design, fabrication and measurement results of a nano-photonic bandgap crystal (PhC) integrated circuit device. The PhC comprises of orthogonally intersecting single line defect Bragg reflection waveguides, partially reflecting PhC mirrors and a small volume optical resonator. A PhC bandgap optical intersection with size of ~ 5 × 5 um, waveguide width of 800 nm, and oper...

Novel physical phenomena can emerge in low-dimensional nanomaterials. Bulk MoS(2), a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS(2) crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d-electron system. This observation shows that quan...