Stephen R Elliott

Learn More
By virtue of the ultrashort phase-transition time of phase-change memory materials, e.g., Ge(2)Sb(2)Te(5), we successfully reproduce the early stages of crystallization in such a material using ab initio molecular-dynamics simulations. A stochastic distribution in the crystallization onset time is found, as generally assumed in classical nucleation theory.(More)
In this paper, we study the local-field enhancement in a system of a metallic nanoparticle placed very near to a dielectric substrate. In such systems, intense electric fields are localized in the gap between the particle and the substrate, creating a 'hot-spot' under appropriate excitation conditions. We use finite-element numerical simulations in order to(More)
A complete system for the simultaneous monitoring of multiple cantilever sensors from different sensor arrays has been developed and tested for gas- and liquid-phase applications. The cantilever sensors are operated in static-deflection mode and the readout is achieved with phase-shifting interferometric microscopy (PSIM). In contrast to existing(More)
Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via(More)
At terahertz frequencies, the libration-vibration motions couple to the dielectric relaxations in disordered hydrogen-bonded solids. The interplay between these processes is still poorly understood, in particular at temperatures below the glass transition temperature, Tg, yet this behavior is of vital importance for the molecular mobility of such materials(More)
The ultrahigh demand for faster computers is currently tackled by traditional methods such as size scaling (for increasing the number of devices), but this is rapidly becoming almost impossible, due to physical and lithographic limitations. To boost the speed of computers without increasing the number of logic devices, one of the most feasible solutions is(More)
According to a report by Frost and Sullivan in 2007, revenues for non-AFIS fingerprint devices in notebook PC's and wireless devices is anticipated to grow from $148.5 million to $1588.0 million by 2014, a compound annual growth rate of 40.3% [1]. The AFIS market has a compound annual growth rate of 15.2% with revenues of $445.0 million in 2007. With the(More)
We describe chalcogenide glass (ChG)-based nanostructures for use as substrates for surface-enhanced Raman scattering (SERS). Such substrates were fabricated by exploiting the photosensitivity of ChG. This allows convenient control of the shape, size, and spacing of the nanostructures. The substrates were used to investigate the sample-concentration and(More)
Carrier-type reversal to enable the formation of semiconductor p-n junctions is a prerequisite for many electronic applications. Chalcogenide glasses are p-type semiconductors and their applications have been limited by the extraordinary difficulty in obtaining n-type conductivity. The ability to form chalcogenide glass p-n junctions could improve the(More)