Double quantum dot turnstile as an electron spin entangler

We study the conditions for a double quantum dot system to work as a reliable electron spin entangler, and the efficiency of a beam splitter as a detector for the resulting entangled electron pairs. In particular, we focus on the relative strengths of the tunneling matrix elements, the applied bias and gate voltage, the necessity of time-dependent input/output barriers, and the consequence of considering wavepacket states for the electrons as they leave the double dot to enter the beam splitter. We show that a double quantum dot turnstile is, in principle, an efficient electron spin entangler or entanglement filter because of the exchange coupling between the dots and the tunable input/output potential barriers, provided certain conditions are satisfied in the experimental set-up.Comment: published version; minor error correcte

Geologic Map of Petrified Forest National Park, Arizona

This geologic dataset covers the area within the boundaries of Petrified Forest National Park (PEFO), located in northeastern Arizona (Figure 1) as defined prior to the expansion approved in December of 2004 (Figure 2); much of the land in the approved expansion has not yet been acquired by the National Park Service, and is inaccessible to the public. The map is based on unpublished mapping by Billingsley (1985b), Johns (1988), Woody (2003), published mapping by Martz and Parker (2010), and new mapping. The geology of the Little Colorado River Valley in eastern Arizona, including the PEFO area (Figures 1, 2), is characterized by widespread exposures of Triassic and Jurassic terrestrial sedimentary rocks. The Upper Triassic Chinle Formation constitutes the bulk of the non-Quaternary exposures within the Park (Figure 3). The Chinle Formation unconformably overlies the Lower- Middle Triassic Moenkopi Formation. Although this latter unit is not exposed within PEFO, widespread exposures are present to the west and south in the Little Colorado River Valley.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]

Cognitive Learning Styles and Digital Equity: Searching for the Middle Way

This research is driven by a desire to understand the lifelong learner in the context of styles of learning and the emerging implications of technology enhanced learning for digital equity. Recognizing cognitive learning styles is the first step educators need to take in order to be most effective in working with students of diversity and bridging across formal and informal settings. Learning environments as a characterising feature of learning styles have undergone unprecedented change over the past decade with learning environments now blending physical and virtual space. To support the increasing diversity of learners pedagogy has to be fair, culturally responsive, equitable and relevant to the ‘virtual generation’. This in turn will inform our understanding of the ‘middle way’ in recognising cognitive learning styles , associated cultural context, and the implications to digital pedagogy equity