Black Joining the Ranks of White: Black Slaveowning in 1800s South Carolina

Exploring the lives and impact of the Black slaveholders in Antebellum South Carolina is a highly overlooked subject in a sensitive area. The idea of a Black slaveholder stands contrary to the widely held belief of slavery held by a majority in the United States. This realization is also startling as most slaveholders were White, with those in bondage being Black. These Black slaveholders actively took part in the system of slavery including the buying and selling of slaves, the production of cash crops, and even support for the eventual Confederacy. Although many began their life in chains, Black future slaveowners would achieve their freedom and purchase their slaves for many reasons. These reasons extend from wanting to save their family from the horrors of slavery to using slaves to achieve their financial goals. These Black slaveowners offer a unique look into the system of slavery and an idea of the differing opinions of slavery held by Black society in the 1800s. This subject is essential to look at as it will offer a unique perspective on the traditional view of the slavery system and how that could impact the years following it

Isotope effects on the lattice parameter of cubic SiC

Path-integral molecular dynamics simulations in the isothermal-isobaric (NPT) ensemble have been carried out to study the dependence of the lattice parameter of 3C-SiC upon isotope mass. This computational method allows a quantitative and nonperturbative study of such anharmonic effect. Atomic nuclei were treated as quantum particles interacting via a tight-binding-type potential. At 300 K, the difference Delta a between lattice parameters of 3C-SiC crystals with 12C and 13C amounts to 2.1 x 10^{-4} A. The effect due to Si isotopes is smaller, and amounts to 3.5 x 10^{-5} A when replacing 28Si by 29Si. Results of the PIMD simulations are interpreted in terms of a quasiharmonic approximation for the lattice vibrations.Comment: 4 pages, 3 figure

N-bit optically controlled microwave signal attenuator using the photoconductive effect

Various optical architectures for N-bit digital control of microwave signals are introduced that use the photoconductive (PC) effect in microwave waveguides for variable rf attenuation control. A 2-bit optically controlled microwave attenuator based on a silicon PC transmission line device is experimentally demonstrated at 990 Mhz. At 532 nm, this attenuator provided 0, 5.8, 11.2, and 15.6 of attenuation levels

Si/SiC bonded wafer: a route to carbon free SiO2 on SiC

This paper describes the thermal oxidation of Si/SiC heterojunction structures, produced using a layer-transfer process, as an alternative solution to fabricating SiC metal-oxide-semiconductor (MOS) devices with lower interface state densities (Dit). Physical characterization demonstrate that the transferred Si layer is relatively smooth, uniform, and essentially monocrystalline. The Si on SiC has been totally or partially thermally oxidized at 900–1150 °C. Dit for both partially and completely oxidized silicon layers on SiC were significantly lower than Dit values for MOS capacitors fabricated via conventional thermal oxidation of SiC. The quality of the SiO2, formed by oxidation of a wafer-bonded silicon layer reported here has the potential to realize a number of innovative heterojunction concepts and devices, including the fabrication of high quality and reliable SiO2 gate oxides

4H–SiC photoconductive switching devices for use in high-power applications

Siliconcarbide is a wide-band-gapsemiconductor suitable for high-power high-voltage devices and it has excellent properties for use in photoconductive semiconductor switches (PCSSs). PCSS were fabricated as planar structures on high-resistivity 4H–SiC and tested at dc bias voltages up to 1000 V. The typical maximum photocurrent of the device at 1000 V was about 49.4 A. The average on-state resistance and the ratio of on-state to off-state currents were about 20 Ω and 3×1011, respectively. Photoconductivity pulse widths for all applied voltages were 8–10 ns. These excellent results are due in part to the removal of the surface damage by high-temperature H2 etching and surface preparation. Atomic force microscopy images revealed that very good surface morphology, atomic layer flatness, and large step width were achieved

A thin film approach for SiC-derived graphene as an on-chip electrode for supercapacitors

© 2015 IOP Publishing Ltd. We designed a nickel-assisted process to obtain graphene with sheet resistance as low as 80 Ω square-1 from silicon carbide films on Si wafers with highly enhanced surface area. The silicon carbide film acts as both a template and source of graphitic carbon, while, simultaneously, the nickel induces porosity on the surface of the film by forming silicides during the annealing process which are subsequently removed. As stand-alone electrodes in supercapacitors, these transfer-free graphene-on-chip samples show a typical double-layer supercapacitive behaviour with gravimetric capacitance of up to 65 F g-1. This work is the first attempt to produce graphene with high surface area from silicon carbide thin films for energy storage at the wafer-level and may open numerous opportunities for on-chip integrated energy storage applications

Nonclassical Light Generation from III-V and Group-IV Solid-State Cavity Quantum Systems

In this chapter, we present the state-of-the-art in the generation of nonclassical states of light using semiconductor cavity quantum electrodynamics (QED) platforms. Our focus is on the photon blockade effects that enable the generation of indistinguishable photon streams with high purity and efficiency. Starting with the leading platform of InGaAs quantum dots in optical nanocavities, we review the physics of a single quantum emitter strongly coupled to a cavity. Furthermore, we propose a complete model for photon blockade and tunneling in III-V quantum dot cavity QED systems. Turning toward quantum emitters with small inhomogeneous broadening, we propose a direction for novel experiments for nonclassical light generation based on group-IV color-center systems. We present a model of a multi-emitter cavity QED platform, which features richer dressed-states ladder structures, and show how it can offer opportunities for studying new regimes of high-quality photon blockade.Comment: 64 pages, 32 figures, to appear as Chapter 3 in Advances in Atomic Molecular and Optical Physics, Vol. 6