Suppression of Shot-Noise in Quantum Cavities: Chaos vs. Disorder

We investigate the behavior of the shot-noise power through quantum mechanical cavities in the semiclassical limit of small electronic wavelength. In the absence of impurity scattering, the Fano factor $F$, giving the noise to current ratio, was previously found to disappear as more and more classical, hence deterministic and noiseless transmission channels open up. We investigate the behavior of $F$ as diffractive impurities are added inside the cavity. We find that $F$ recovers its universal value provided (i) impurities cover the full cavity so that only a set of zero measure of classical trajectories may avoid them, and (ii) the impurity scattering rate exceeds the inverse dwell time through the cavity. If condition (i) is not satisfied, $F$ saturates below its universal value, even in the limit of strong scattering. Our results corroborate the validity of the two-phase fluid model according to which the electronic flow splits into two well separated components, a classical deterministic fluid and a stochastic quantum-mechanical fluid. Only the latter carries shot-noise.Comment: 6 pages, 3 figures, to appear in the proceedings of the fourth conference on ``Unsolved Problems of Noise and Fluctuations in Physics, Biology and High Technology'

Creating An Information Technology Security Program for Educators

Information Technology (IT) Security education has become a critical component to college curriculum within the past few years. Along with developing security courses and degrees, there is a need to train college educators and disseminate the security curriculum and best-practices to other colleges. St. Petersburg College implemented a project entitled Information Technology Security and Education for Educators (ITSCEE) designed to address Priority III of the “National Strategy to Secure Cyberspace”, establishment of a “national cyberspace training program.” The project was designed to produce three nationally relevant IT Security degree and certificate programs at the associate, advanced technical certificate, and baccalaureate levels. Also, the project was designed to provide training and an opportunity for the Florida Community College Faculty to obtain certification in the IT Security arena to assist their institutions in deploying relevant IT Security degree programs. This paper will describe the evolution of this project, the success in meeting goals, lessons learned and techniques and best practices other colleges may use to enhance their programs

Modulation of near-field heat transfer between two gratings

We present a theoretical study of near-field heat transfer between two uniaxial anisotropic planar structures. We investigate how the distance and relative orientation (with respect to their optical axes) between the objects affect the heat flux. In particular, we show that by changing the angle between the optical axes it is possible in certain cases to modulate the net heat flux up to 90% at room temperature, and discuss possible applications of such a strong effect

Weak-lensing BB-modes as a probe of the isotropy of the universe

We compute the angular power spectrum of the $B$-modes of the weak-lensing shear in a spatially anisotropic spacetime. We find that there must also exist off-diagonal correlations between the $E$-modes, $B$-modes, and convergence that allow one to reconstruct the eigendirections of expansion. Focusing on future surveys such as Euclid and SKA, we show that observations can constrain the geometrical shear in units of the Hubble rate at the percent level, or even better, offering a new and powerful method to probe our cosmological model.Comment: 4 pages, 3 figures. This version matches the published on