175 GHz, 400-fs-pulse harmonically mode-locked surface emitting semiconductor laser

We report a harmonically mode-locked vertical external cavity surface emitting laser (VECSEL) producing 400 fs pulses at a repetition frequency of 175 GHz with an average output power of 300 mW. Harmonic mode-locking was established using a 300 µm thick intracavity single crystal diamond heat spreader in thermal contact with the front surface of the gain sample using liquid capillary bonding. The repetition frequency was set by the diamond microcavity and stable harmonic mode locking was achieved when the laser cavity length was tuned so that the laser operated on the 117th harmonic of the fundamental cavity. When an etalon placed intracavity next to the gain sample, but not in thermal contact was used pulse groups were observed. These contained 300 fs pulses with a spacing of 5.9 ps. We conclude that to achieve stable harmonic mode locking at repetition frequencies in the 100s of GHz range in a VECSEL there is a threshold pulse energy above which harmonic mode locking is achieved and below which groups of pulses are observed

Spin Triplet Supercurrent in Co/Ni Multilayer Josephson Junctions with Perpendicular Anisotropy

We have measured spin-triplet supercurrent in Josephson junctions of the form S/F'/F/F'/S, where S is superconducting Nb, F' is a thin Ni layer with in-plane magnetization, and F is a Ni/[Co/Ni]n multilayer with out-of-plane magnetization. The supercurrent in these junctions decays very slowly with F-layer thickness, and is much larger than in similar junctions not containing the two F' layers. Those two features are the characteristic signatures of spin-triplet supercurrent, which is maximized by the orthogonality of the magnetizations in the F and F' layers. Magnetic measurements confirm the out-of-plane anisotropy of the Co/Ni multilayers. These samples have their critical current optimized in the as-prepared state, which will be useful for future applications.Comment: 4 pages, 4 figures, formatted in RevTeX version 4. Submitted to Physical Review B on August 13th, 201

Demographic Characteristics of Academic Advisors for Intercollegiate Athletics of NCAA D-I Member Institutions

This investigation examined selected demographic factors of National Association of Academic Advisors for Atlhetics (N4A) professionals. A 23 item self-reported questionnaire was mailed in Spring 2001. A non-experimental descriptive exploratory design was implemented utilizing the field survey format. Research variables investigated were individual primary & secondary diversity characteristics. Primary diversity characteristics refer to human differences that are inborn and cannot be changed or modified during a person's life such as age, race, ethnicity, gender, physical abilities, and sexual orientation (Gardenswartz & Rowe, 1994). Secondary diversity characteristics are human differences that are inherited from the environment and can be changed or modified during a person's life such as educational level, work experience, income, marital status, religious beliefs, geographical location, parental status, behavioral style, etc. (Loden & Rosener, 1991). The responses from 213 questionnaires were coded and included in the SPSS computer analysis. Not all participants responded to all items; as a result, the sample sub-totals varied from 202-213. Results indicated 2/3 (67.4%) of advisors were likely to be 39 years or less in age and 113 (32.6%) were 40 years or older. Cross-tabulations implied male and female advisors were likely to have earned degrees at the same levels. White females were more often employed as academic athletic advisors in NCAA D-1 institutions than male or females of other ethnic minority groups collectively. Gender results from 212 responses indicated 83 (39.3%) were males and 129 (60.7%) were females. The average age of the respondents was 36.9 years and they ranged in age from 23 to 66 years (median age 34; mode age 29). Annual mean salaries of the advisors were $40,956 and ranged from$18,000 to $96,000 (median salary$39,000, mode $30,000). The average salary for the male advisors was 8.45$6,804 higher han the average salary for the female advisors. A similar trend was also shown for salary. The median salary for male advisors was $42,000 and$36,000 for female advisors. The difference in salary depicted an 8.57% or $6,000 increase for the males than female

Statistical Data Analysis Techniques Employed in Sport Marketing Quarterly: 1992 to 2004

This investigation was an assessment of data analysis statistical techniques used in Sport Marketing Quarterly (SMQ) from 1992 to 2004. In 159 quantitative data based articles reviewed, 360 uses of statistical data analysis techniques were identified. The techniques were classified by type of statistical data analysis method as descriptive statistics, parametric statistics, and nonparametric statistics. One half (50.00%) were used as descriptive statistics, 41.94% as parametric statistics, and less than one tenth (8.06%) as nonparametric statistics. Percentages and frequencies were the most frequent descriptive statistics used to answer the research purposes, questions, and/or hypotheses by the researchers of SMQ for this period. One-way ANOVA and regression analysis were the most frequent parametric statistics used and chi-square was the most frequent nonparametric statistic used. The intent of this investigation was to provide undergraduate and graduate students, their instructors, and other scholars with an overview of the most frequently used statistical data analysis techniques used in SMQ during its first 13 years. In addition, this study has provided some insight into the directions of the research conducted in sport marketing studies from a research methodology standpoint. For a new and developing academic area such as sport marketing, it is important for its consumers to know how such an area advances relative to its research methods

Correlations in intermediate-energy two-proton removal reactions

We report final-state-exclusive measurements of the light charged fragments in coincidence with 26Ne residual nuclei following the direct two-proton removal from a neutron-rich 28Mg secondary beam. A Dalitz-plot analysis and comparisons with simulations show that a majority of the triple- coincidence events with two protons display phase-space correlations consistent with the (two-body) kinematics of a spatially-correlated pair-removal mechanism. The fraction of such correlated events, 56(12) %, is consistent with the fraction of the calculated cross section, 64 %, arising from spin S = 0 two-proton configurations in the entrance-channel (shell-model) 28Mg ground state wave function. This result promises access to an additional and more specific probe of the spin and spatial correlations of valence nucleon pairs in exotic nuclei produced as fast secondary beams.Comment: accepted for publication in Physical Review Letter

Simulation of metallic nanostructures for emission of THz radiation using the lateral photo-Dember effect

A 2D simulation for the lateral photo-Dember effect is used to calculate the THz emission of metallic nanostructures due to ultrafast diffusion of carriers in order to realize a series of THz emitters.Comment: Corrected version of a paper given at 2011 36th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz

First-order phase transition vs. spin-state quantum-critical scenarios in strain-tuned epitaxial cobaltite thin films

Pr-containing perovskite cobaltites exhibit unusual valence transitions, coupled to coincident structural, spin-state, and metal-insulator transitions. Heteroepitaxial strain was recently used to control these phenomena in the model (Pr$_{1-y}$Y$_y$)$_{1-x}$Ca$_x$CoO$_{3-\delta}$ system, stabilizing a nonmagnetic insulating phase under compression (with a room-temperature valence/spin-state/metal-insulator transition) and a ferromagnetic metallic phase under tension, thus exposing a potential spin-state quantum critical point. The latter has been proposed in cobaltites and can be probed in this system as a function of a disorder-free variable (strain). We study this here via thickness-dependent strain relaxation in compressive SrLaAlO$_4$(001)/(Pr$_{0.85}$Y$_{0.15}$)$_{0.70}$Ca$_{0.30}$CoO$_{3-\delta}$ epitaxial thin films to quasi-continuously probe structural, electronic, and magnetic behaviors across the nonmagnetic-insulator/ferromagnetic-metal boundary. High-resolution X-ray diffraction, electronic transport, magnetometry, polarized neutron reflectometry, and temperature-dependent magnetic force microscopy provide a detailed picture, including abundant evidence of temperature- and strain-dependent phase coexistence. This indicates a first-order phase transition as opposed to spin-state quantum-critical behavior, which we discuss theoretically via a phenomenological Landau model for coupled spin-state and magnetic phase transitions.Comment: main text + supplementary materia