Analytical solution of generalized Burton--Cabrera--Frank equations for growth and post--growth equilibration on vicinal surfaces

We investigate growth on vicinal surfaces by molecular beam epitaxy making use of a generalized Burton--Cabrera--Frank model. Our primary aim is to propose and implement a novel analytical program based on a perturbative solution of the non--linear equations describing the coupled adatom and dimer kinetics. These equations are considered as originating from a fully microscopic description that allows the step boundary conditions to be directly formulated in terms of the sticking coefficients at each step. As an example, we study the importance of diffusion barriers for adatoms hopping down descending steps (Schwoebel effect) during growth and post-growth equilibration of the surface.Comment: 16 pages, REVTeX 3.0, IC-DDV-94-00

Dynamic manipulation of mechanical resonators in the high amplitude regime through optical backaction

Cavity optomechanics enables active manipulation of mechanical resonators through backaction cooling and amplification. This ability to control mechanical motion with retarded optical forces has recently spurred a race towards realizing a mechanical resonator in its quantum ground state. Here, instead of quenching optomechanical motion, we demonstrate high amplitude operation of nanomechanical resonators by utilizing a highly efficient phonon generation process. In this regime, the nanomechanical resonators gain sufficient energy from the optical field to overcome the large energy barrier of a double well potential, leading to nanomechanical slow-down and zero frequency singularity, as predicted by early theories . Besides fundamental studies and interests in parametric amplification of small forces, optomechanical backaction is also projected to open new windows for studying discrete mechanical states, and to foster applications. Here we realize a non-volatile mechanical memory element, in which bits are written and reset via optomechanical backaction by controlling the mechanical damping across the barrier. Our study casts a new perspective on the energy dynamics in coupled mechanical resonator - cavity systems and enables novel functional devices that utilize the principles of cavity optomechanics.Comment: 22 pages, 5 figure

Fueling the gender gap? Oil and women's labor and marriage market outcomes

This paper analyzes the effect of resource-based economic specialization on women's labor market outcomes. Using information on the location and discovery of major oil fields in the Southern United States coupled with a county-level panel derived from US Census data for 1900-1940, we specifically test the hypothesis that the presence of mineral resources can induce changes in the sectoral composition of the local economy that are detrimental to women's labor market outcomes. We find evidence that the discovery of oil at the county level may constitute a substantial male biased demand shock to local labor markets, as it is associated with a higher gender pay gap. However, we find no evidence that oil wealth lowers female labor force participation or has any impact on local marriage and fertility patterns. While our results are consistent with oil shocks limiting female labor market opportunities in some sectors (mainly manufacturing), this effect tends to be compensated by the higher availability of service sector jobs for women who are therefore not driven out of the labor market

The Ninth Visual Object Tracking VOT2021 Challenge Results

acceptedVersionPeer reviewe