We consider the spin injection from Fe into ZnSe and GaAs in the ballistic limit. By means of the ab initio screened Korringa-Kohn-Rostoker method we calculate the ground-state properties of epitaxial FeuZnSe(001) and FeuGaAs(001) heterostructures. Three injection processes are considered: injection of hot electrons and injection of ‘‘thermal’’ electrons with and without an interface barrier. T...

We report electrical transport experiments, using the phenomenon of electrical breakdown to perform thermometry, that probe the thermal properties of individual multiwalled carbon nanotubes. Our results show that nanotubes can readily conduct heat by ballistic phonon propagation. We determine the thermal conductance quantum, the ultimate limit to thermal conductance for a single phonon channel,...

Investigations of diffusive-ballistic heat conduction of finite-length single-walled carbon nanotubes and nanographene ribbons at room temperature have been carried out by using nonequilibrium molecular dynamics simulations. The length dependences of thermal conductivity reveal the variation of the balance between ballistic and diffusive heat conduction. For both systems, the profile indicates ...

Gregory Koblentz is a Junior Fellow with the Nuclear Non-Proliferation Project at the Carnegie Endowment for International Peace in Washington, D.C. The missile competition in South Asia is on the verge of a new and dangerous phase that threatens to disrupt the delicate strategic balance of the subcontinent. India and Pakistan already have stockpiles of ballistic missiles, along with the associ...

The attractiveness of both ballistic missiles and weapons of mass destruction (WMD) to various actors throughout the world represents a serious threat to U.S. security. These weapons and delivery systems are popular in part because they are highly visible symbols of military prowess. As such, they provide significant influence on regional balances of power, even among friends and allies. Furthe...

We present results of a model of sequential adsorption in which the adsorbing particles are correlated with the particles attached to the substrate. The strength of the correlations is measured by a tunable parameter sigma. The model interpolates between free ballistic adsorption in the limit sigma-->infinity and a strongly correlated phase, appearing for sigma-->0 and characterized by the emer...

We study the one-dimensional ballistic aggregation process in the continuum limit for one-sided Brownian initial velocity (i.e. particles merge when they collide and move freely between collisions, and in the continuum limit the initial velocity on the right side is a Brownian motion that starts from the origin x = 0). We consider the cases where the left side is either at rest or empty at t = ...

We have shown experimentally that the thermal conductance through discrete, one-dimensional, ballistic phonon channels is quantized, G=πkB T/3h[1,2]. We have developed novel, 3D nanostructures, with feature sizes of order ~100nm to enter and reveal this mesoscopic limit for phonons. We will describe the techniques and implications of this measurement, and describe work in progress where we will...

We present a semiclassical theory for the scattering matrix S of a chaotic ballistic cavity at finite Ehrenfest time. Using a phase-space representation coupled with a multibounce expansion, we show how the Liouville conservation of phase-space volume decomposes S as S=S(cl) plus sign in circle S(qm). The short-time, classical contribution S(cl) generates deterministic transmission eigenvalues ...