Effects of depolarizing quantum channels on BB84 and SARG04 quantum cryptography protocols

We report experimental studies on the effect of the depolarizing quantum channel on weak-pulse BB84 and SARG04 quantum cryptography. The experimental results show that, in real world conditions in which channel depolarization cannot be ignored, BB84 should perform better than SARG04.Comment: 4 pages, 4 figure

Carbon deposition on hematite (α\alpha-Fe2_2O3_3) nanocubes by an annealing in the air: morphology study with grazing incidence small angle X-ray scattering (GISAXS)

GISAXS has been used to study morphology change of $\alpha$-Fe$_2$O$_3$ nanocubes after annealing processes. A submonolayer of the nanocubes was deposited on a Si(100) substrate. While an annealing at 400 $^\circ$C in a vacuum does not change a GISAXS pattern from as-prepared nanocubes submonolayer, annealing in the air at the same temperature altered the GISAXS pattern significantly. SEM image showed that the air-annealed nanocubes were coated with thin layers which were identified as amorphous carbon layers based on Raman measurements. GISAXS simulations from morphologies of nanocube with 38 nm side-length and core-shell (nanocube-core and 7 nm thick carbon-shell) nicely reproduced measured patterns from the vacuum annealed and the air-annealed nanocubes, respectively. The current study provides new approach for in-situ characterization of carbon deposition on a uniform shape nanoparticle through monitoring of deposited carbon thickness.Comment: 15 pages, 6 figure

A study on the turbulent transport of an advective nature in the fluid plasma

Advective nature of the electrostatic turbulent flux of plasma energy is studied numerically in a nearly adiabatic state. Such a state is represented by the Hasegawa-Mima equation that is driven by a noise that may model the destabilization due to the phase mismatch of the plasma density and the electric potential. The noise is assumed to be Gaussian and not to be invariant under reflection along a direction $\hat s$. It is found that the flux density induced by such noise is anisotropic: While it is random along $\hat s$, it is not along the perpendicular direction ${\hat s}_\perp$ and the flux is not diffusive. The renormalized response may be approximated as advective with the velocity being proportional to $(k\rho_s)^2$ in the Fourier space $\vec k$

Suppressed Superconductivity of the Surface Conduction Layer in Bi2_2Sr2_2CaCu2_2O8+x_{8+x} Single Crystals Probed by {\it c}-Axis Tunneling Measurements

We fabricated small-size stacks on the surface of Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO-2212) single crystals with the bulk transition temperature $T_c$$\simeq$90 K, each containing a few intrinsic Josephson junctions. Below a critical temperature $T_c'$ ($\ll$ $T_c$), we have observed a weakened Josephson coupling between the CuO$_2$ superconducting double layer at the crystal surface and the adjacent one located deeper inside a stack. The quasiparticle branch in the $IV$ data of the weakened Josephson junction (WJJ) fits well to the tunneling characteristics of a d-wave superconductor($'$)/insulator/d-wave superconductor (D$'$ID) junction. Also, the tunneling resistance in the range $T_c'$$<$$T$$<$$T_c$ agrees well with the tunneling in a normal metal/insulator/d-wave superconductor (NID) junction. In spite of the suppressed superconductivity at the surface layer the symmetry of the order parameter appears to remain unaffected.Comment: 13 pages, 6 figure

A cyberciege traffic analysis extension for teaching network security

CyberCIEGE is an interactive game simulating realistic scenarios that teaches the players Information Assurance (IA) concepts. The existing game scenarios only provide a high-level abstraction of the networked environment, e.g., nodes do not have Internet protocol (IP) addresses or belong to proper subnets, and there is no packet-level network simulation. This research explored endowing the game with network level traffic analysis, and implementing a game scenario to take advantage of this new capability. Traffic analysis is presented to players in a format similar to existing tools such that learned skills may be easily transferred to future real-world situations. A network traffic analysis tool simulation within CyberCIEGE was developed and this new tool provides the player with traffic analysis capability. Using existing taxonomies of cyber-attacks, the research identified a subset of network-based attacks most amenable to modeling and representation within CyberCIEGE. From the attacks identified, a complementary CyberCIEGE scenario was developed to provide the player with new educational opportunities for network analysis and threat identification. From the attack scenario, players also learn about the effects of these cyber-attacks and glean a more informed understanding of appropriate mitigation measures.http://archive.org/details/acyberciegetraff109451057