Welding of commercial base plates is investigated

Investigation of aluminum alloy welds reveals that the combinations of metallic elements with hydrogen are not capable of producing weld porosity themselves, rather they tend to increase the amount of porosity only in the presence of arc contamination by water vapor

A heralded quantum gate between remote quantum memories

We demonstrate a probabilistic entangling quantum gate between two distant trapped ytterbium ions. The gate is implemented between the hyperfine "clock" state atomic qubits and mediated by the interference of two emitted photons carrying frequency encoded qubits. Heralded by the coincidence detection of these two photons, the gate has an average fidelity of 90+-2%. This entangling gate together with single qubit operations is sufficient to generate large entangled cluster states for scalable quantum computing

Sympathetic Cooling of Trapped Cd+ Isotopes

We sympathetically cool a trapped 112Cd+ ion by directly Doppler-cooling a 114Cd+ ion in the same trap. This is the first demonstration of optically addressing a single trapped ion being sympathetically cooled by a different species ion. Notably, the experiment uses a single laser source, and does not require strong focusing. This paves the way toward reducing decoherence in an ion trap quantum computer based on Cd+ isotopes.Comment: 4 figure

Preparing encoded states in an oscillator

Recently a scheme has been proposed for constructing quantum error-correcting codes that embed a finite-dimensional code space in the infinite-dimensional Hilbert space of a system described by continuous quantum variables. One of the difficult steps in this scheme is the preparation of the encoded states. We show how these states can be generated by coupling a continuous quantum variable to a single qubit. An ion trap quantum computer provides a natural setting for a continuous system coupled to a qubit. We discuss how encoded states may be generated in an ion trap.Comment: 5 pages, 4 figures, RevTe

Realization of a Decoherence-free, Optimally Distinguishable Mesoscopic Quantum Superposition

We report the realization of an entangled quantum superposition of M=12 photons by a high gain, quantum-injected optical parametric amplification. The system is found so highly resilient against decoherence to exhibit directly accessible mesoscopic interference effects at normal temperature. By modern tomographic methods the non-separability and the quantum superposition are demonstrated for the overall mesoscopic output state of the dynamic ''closed system''. The device realizes the condition conceived by Erwin Schroedinger with his 1935 paradigmatic ''Cat'' apologue, a fundamental landmark in quantum mechanics.Comment: 10 pages, 3 figure

Cooling the Collective Motion of Trapped Ions to Initialize a Quantum Register

We report preparation in the ground state of collective modes of motion of two trapped 9Be+ ions. This is a crucial step towards realizing quantum logic gates which can entangle the ions' internal electronic states. We find that heating of the modes of relative ion motion is substantially suppressed relative to that of the center-of-mass modes, suggesting the importance of these modes in future experiments.Comment: 5 pages, including 3 figures. RevTeX. PDF and PostScript available at http://www.bldrdoc.gov/timefreq/ion/qucomp/papers.htm . final (published) version. Eq. 1 and Table 1 slightly different from original submissio

The Value of Education Between Two African American Male Populations in a Rural Southern Community

This study identified perceptions of education by low performing and college track African American males in a rural town in Southern Kentucky. Through the lens of Critical Race Theory and Symbolic Interactionism, the researchers explored how 16 young men value a secondary and postsecondary education. Selected by their administrator at two high schools, the males were identified as college track or low performing. The findings revealed that both groups identify racial relations as a barrier to educational achievement; however, college track males believed education would assist in overcoming racial divides. Additional findings highlight a difference in perception based upon the presence of a male role model, the home environment, and the felt need for survival. Based on the findings, recommendations include model programs and collaborations among societal groups within the young age; a need for male social programs that foster and encourage positivity throughout a young male’s life; and the need for local resources to assist and encourage young African American males to pursue a postsecondary education