Magnetically Defined Qubits on 3D Topological Insulators

We explore potentials that break time-reversal symmetry to confine the surface states of 3D topological insulators into quantum wires and quantum dots. A magnetic domain wall on a ferromagnet insulator cap layer provides interfacial states predicted to show the quantum anomalous Hall effect (QAHE). Here we show that confinement can also occur at magnetic domain heterostructures, with states extended in the inner domain, as well as interfacial QAHE states at the surrounding domain walls. The proposed geometry allows the isolation of the wire and dot from spurious circumventing surface states. For the quantum dots we find that highly spin-polarized quantized QAHE states at the dot edge constitute a promising candidate for quantum computing qubits.Comment: 5 pages, 4 figure

Social Media Usage Patterns: Research Note Regarding the Lack of Universal Validated Measures for Active and Passive Use

The existing literature regarding social media use provides extant evidence supporting the claim that usage patterns ultimately have the capability of impacting users. However, the vast majority of the literature is based upon experimental laboratory settings where participants are observed by researchers. The current article asserts that there is a significant deficiency within the discipline regarding the validated measurement of usage patterns of social networking sites (SNSs) and offers guidance for those who may want to develop a general measure

Many-body effects on the ρxx\rho_{xx} ringlike structures in two-subband wells

The longitudinal resistivity $\rho_{xx}$ of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density--magnetic-field diagram, due to the crossings of spin-split Landau levels (LLs) from distinct subbands. Using spin density functional theory and linear response, we investigate the shape and spin polarization of these structures as a function of temperature and magnetic-field tilt angle. We find that (i) some of the rings "break" at sufficiently low temperatures due to a quantum Hall ferromagnetic phase transition, thus exhibiting a high degree of spin polarization ($\sim 50$%) within, consistent with the NMR data of Zhang \textit{et al.} [Phys. Rev. Lett. {\bf 98}, 246802 (2007)], and (ii) for increasing tilting angles the interplay between the anticrossings due to inter-LL couplings and the exchange-correlation (XC) effects leads to a collapse of the rings at some critical angle $\theta_c$, in agreement with the data of Guo \textit{et al.} [Phys. Rev. B {\bf 78}, 233305 (2008)].Comment: 4 pages, 3 figure

Horatio Nelson Lay: His Role in British Relations With China 1849-1865.

An attempt has been made in this study to trace the background, and China career, of Horatio Nelson Lay, an Englishman, who began his public service in the British consular establishment in China and who concluded it in the service of the Ch'ing Imperial government. He achieved notoriety, successively, as British Inspector in the Shanghai foreign customs administration inaugurated in 1854, as interpreter-negotiator in the treaty settlements of Tientsin and Shanghai of 1858, as first Inspector-General of the Imperial Maritime Custom Service and as one of the principals in the development of a European-Chinese naval force (the Lay-Osborn Flotilla), which was disbanded when rejected by the Ch'ing government in 1863. Lay's dismissal followed immediately after this event. The study discloses that the activities, while carrying out the functions related to these responsibilities, placed him in a key position to influence various aspects of British relations with China during the period. A thesis, based on evaluations of his influence has been formulated, which focusses on an analysis of the nature of his dual role as a servant both of British (occident-oriented) and Ch'ing (Confucian-oriented) interests. The re-examination of evidence previously available and of newly discovered evidence provides the basis for a re-evaluation of his career. The principal conclusions conveyed by the investigation, analysis and evaluation of the larger body of evidence fall into two categories. As for the direct effects of his influence, except for his contributions to the consolidation of the foreign Inspectorate customs administration, the influence he himself claimed, as well as that ascribed to him by his contemporaries, has been overstated. As for the indirect effects, his contribution to the process of "dialog", a pre-requisite for achieving effective intercourse, was appreciable

Dimensionality of the Iowa-Netherlands Comparison Orientation Measure and its relationship to Reinforcement Sensitivity Theory

The aims of this study were, first, to reassess the factor structure of the Iowa-Netherlands Social Comparison Orientation Measure (INCOM) and, second, to explore the associations of its factors with the Reinforcement Sensitivity Theory (RST) of personality. Data from 337 respondents were collected via online questionnaire. Structural equation models were used to assess the factor structure of the INCOM and test for relationships with RST traits. The results confirmed previous findings that the INCOM contains two factors: Ability, which relates to the comparison of performance, and Opinion, which relates to the comparison of thoughts and emotions. The two-factor model was found to be superior to the commonly used 1-factor solution. The models further revealed significant relationships with RST factors: positive associations between the Ability factor and the Behavioral Inhibition System (BIS) and Behavioural Approach System (BAS) Reward Reactivity; positive associations between the Opinion factor and BAS Reward Reactivity and Goal-Drive Persistence, and a negative association with BAS Impulsivity. These findings indicate that using the INCOM as a single scale is likely to miss significant unique relationships. Our findings also provide new insight into how individual differences in personality may influence social comparison behavior

Passive and Active Facebook Use Measure (PAUM): Validation and relationship to the Reinforcement Sensitivity Theory

The aims of this study were to design and validate a questionnaire to measure passive and active Facebook use, and to explore the associations of these factors with the Reinforcement Sensitivity Theory (RST) of personality. Passive Facebook use describes the consumption but not the creation of content, while active Facebook use describes active engagement with the site. As Facebook has many features, users may interact with the site differently, thereby creating conflicting results when general use measures are assessed independently. To address this issue, we developed a 13-item questionnaire which reflects three levels of Facebook engagement: Active social, Active non-social, and Passive use. These three multi-item scales demonstrate sufficient internal reliability and discriminant validity. To further investigate individual differences in Facebook use, we used regressions to assess the associations between RST and the factors of the Passive Active Use Measure (PAUM). Reward Reactivity was positively associated with both Active social and Passive use. Impulsivity and Goal-Drive Persistence were positively associated with Active non-social use. FFFS was positively associated with Passive use, and Reward Interest was positively associated with all three PAUM factors. The findings of this study highlight how individual differences impact the way users engage with Facebook

Handicapped Discrimination Law and the Americans with Disabilities Act

Symposium - Introduction to Labor and Employment La