Trapped-ion qutrit spin molecule quantum computer

We present a qutrit quantum computer design using trapped ions in the presence of a magnetic field gradient. The magnetic field gradient induces a "spin-spin" type coupling, similar to the J-coupling observed in molecules, between the qutrits which allows conditional quantum logic to take place. We describe in some detail, how one can execute specific one and two qutrit quantum gates, required for universal qutrit quantum computing.Comment: 4 pages, 2 figure

Variable mixer propulsion cycle

A design technique, method and apparatus are delineated for controlling the bypass gas stream pressure and varying the bypass ratio of a mixed flow gas turbine engine in order to achieve improved performance. The disclosed embodiments each include a mixing device for combining the core and bypass gas streams. The variable area mixing device permits the static pressures of the core and bypass streams to be balanced prior to mixing at widely varying bypass stream pressure levels. The mixed flow gas turbine engine therefore operates efficiently over a wide range of bypass ratios and the dynamic pressure of the bypass stream is maintained at a level which will keep the engine inlet airflow matched to an optimum design level throughout a wide range of engine thrust settings

A problem for downward closure in the semantics of counterfactuals

Ciardelli et al. (2018) adopt the framework of inquisitive semantics to provide a novel semantics for counterfactuals. They argue in favour of adopting inquisitive semantics based on experimental evidence that De Morgan's law, which fails in inquisitive semantics, is invalid in counterfactual antecedents. We show that a unique feature of inquisitive semantics—the fact that its meanings are downward closed—undermines Ciardelli et al. (2018)'s semantic account of their data. The scenarios we consider suggest either adopting a semantic framework other than inquisitive semantics, or developing a non-semantic explanation of the phenomena Ciardelli et al. (2018) seek to explain

Climb High : Sondheim at the gateway to his career

Sondheim has long identified his mentor, Oscar Hammerstein II, as one of the most influential figures in his life, both personally and creatively. In one interview, he called Hammerstein ‘a surrogate father’ and disclosed that ‘[h]e taught me how to structure a song, what a character was, what a scene was; he taught me how to tell a story, how not to tell a story, how to make stage directions practical’. The vehicle for this training was a four-part project: Hammerstein challenged the young Sondheim to write four musicals with specific criteria. The first three of these were abandoned before completion but Sondheim wrote a full script, music and lyrics for Climb High, working on the project from 1950 to 1953 with the obvious hope of having Hammerstein produce it on the stage (a frustrated ambition). Yet very little has been written about the work and Sondheim himself has been at pains to downplay its importance in his overall output. In this article, I exploit archival documents from Sondheim’s papers at Madison, Wisconsin to shed new light on the process of writing the piece, as well as its many anticipations of Sondheim’s mature work. In this way, I will place Climb High in the context of Sondheim’s creative development: a flawed but fascinating document of a writer at the gateway to his professional career