389 research outputs found

    Topological phase transitions and quantum Hall effect in the graphene family

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    Monolayer staggered materials of the graphene family present intrinsic spin-orbit coupling and can be driven through several topological phase transitions using external circularly polarized lasers and static electric or magnetic fields. We show how topological features arising from photoinduced phase transitions and the magnetic-field-induced quantum Hall effect coexist in these materials and simultaneously impact their Hall conductivity through their corresponding charge Chern numbers. We also show that the spectral response of the longitudinal conductivity contains signatures of the various phase-transition boundaries, that the transverse conductivity encodes information about the topology of the band structure, and that both present resonant peaks which can be unequivocally associated with one of the four inequivalent Dirac cones present in these materials. This complex optoelectronic response can be probed with straightforward Faraday rotation experiments, allowing the study of the crossroads between quantum Hall physics, spintronics, and valleytronics

    Exploring the attitudes of students undertaking sports degrees towards online international learning

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    Abstract Aims: There is an increased focus on the internationalisation of the learning experiences of university students1. One way this can be achieved is through ‘virtual internationalisation’2, which can be promoted through the use of Online International Learning (OIL) programmes. This article on sport pedagogy investigates the attitudes of sport students to such a programme. Methods: This article uses quantitative and qualitative methods. 63 students completed a survey and wrote reflective reports. Data was collected from a survey of 16 targeted questions addressing the attitudes of students towards the programme. Students also wrote reflective reports on their experiences, allowing for qualitative responses to be analysed. Results: 62% of students surveyed found the internationalised module to have been a worthwhile experience in terms of learning new skills and working with a partner from an institution based in another continent. 65% suggested that they learned skills on the internationalised module they would use again in education and in future employment. Students from European Union countries gave high rates of positive feedback. 100% reported that the module was a worthwhile experience, compared to 60% of UK students and 38% of international students from outside the European Union. Conclusion: 62% of students surveyed stated that they learned new skills, and there was a perceived value to the programme in terms of enhancing employment prospects. Virtual mobilities projects offer a possible method for tutors to give students international experiences, which is important as sport is now a globalised industry

    ‘Getting inside the wicket’: strategies for the social inclusion of British Pakistani Muslim cricketers

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    The England and Wales Cricket Board (ECB) are keen to increase the participation of British Asian groups, including those of British Pakistani Muslim (BPM) backgrounds, at mainstream levels of the game in order to meet their twin strategic aims of raising participation levels and fostering elite development. We argue that the potential to include BPM men in and through cricket is achievable, but strategies to engage them must address their social needs and circumstances rather than be superficial and tokenistic. Cricket agencies and bodies must be willing to adapt and change to become more inclusive, and indeed supportive of real meritocracy. Using research testimonies garnered from interviews with BPM men who play cricket at amateur mainstream and/or alternative formats of the game, we identify and forward strategies that can be activated by cricket development officers in order to create new possibilities for the social inclusion of BPM men

    Early Cenozoic Fluvial Deposits of the Renova Formation in SW Montana: Links to Southern Nevada and Utah?

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    Examination of the early Cenozoic fluvial deposits of the Renova Formation provides support for the hypothesis that a southern branch of the pre-ice age Bell River of Canada, a river thought to have been the size of the Amazon, may have originated in the southern Colorado Plateau and flowed northward through Nevada, Utah, Idaho, and Montana. The Renova Formation mostly comprises fluvially-reworked and degraded volcanic ash. Radiometric ages of zircon grains from the Renova Formation, reported in the literature, correlate with the ages of zircons from ash-flow tuffs that erupted from mega-calderas in southern Nevada and Utah. There are also older zircons present in the Renova deposits which indicate recycling of zircon grains from Precambrian and Cambrian quartzites of Utah. These results provide evidence of river transport of ash and sand from Nevada and Utah into Montana. Previous research has been reviewed and assessed in the context of the Bell River hypothesis. A field trip was taken to physically observe the composition and depositional features of the Renova. Histograms generated by mass spectroscopy of Renova Formation zircon have been re-analyzed in light of the mega-caldera origin hypothesis. This new model suggests that a major, north-flowing Cenozoic drainage system was present in the western interior of North America before being segmented and destroyed by faulting and volcanism

    Emerging roles of ATF2 and the dynamic AP1 network in cancer

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    Cooperation among transcription factors is central for their ability to execute specific transcriptional programmes. The AP1 complex exemplifies a network of transcription factors that function in unison under normal circumstances and during the course of tumour development and progression. This Perspective summarizes our current understanding of the changes in members of the AP1 complex and the role of ATF2 as part of this complex in tumorigenesis.Fil: Lopez Bergami, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Lau, Eric . Burnham Institute for Medical Research; Estados UnidosFil: Ronai, Zeev . Burnham Institute for Medical Research; Estados Unido

    Superfluid stiffness of twisted multilayer graphene superconductors

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    The robustness of the macroscopic quantum nature of a superconductor can be characterized by the superfluid stiffness, ρs\rho_s, a quantity that describes the energy required to vary the phase of the macroscopic quantum wave function. In unconventional superconductors, such as cuprates, the low-temperature behavior of ρs\rho_s drastically differs from that of conventional superconductors due to quasiparticle excitations from gapless points (nodes) in momentum space. Intensive research on the recently discovered magic-angle twisted graphene family has revealed, in addition to superconducting states, strongly correlated electronic states associated with spontaneously broken symmetries, inviting the study of ρs\rho_s to uncover the potentially unconventional nature of its superconductivity. Here we report the measurement of ρs\rho_s in magic-angle twisted trilayer graphene (TTG), revealing unconventional nodal-gap superconductivity. Utilizing radio-frequency reflectometry techniques to measure the kinetic inductive response of superconducting TTG coupled to a microwave resonator, we find a linear temperature dependence of ρs\rho_s at low temperatures and nonlinear Meissner effects in the current bias dependence, both indicating nodal structures in the superconducting order parameter. Furthermore, the doping dependence shows a linear correlation between the zero temperature ρs\rho_s and the superconducting transition temperature TcT_c, reminiscent of Uemura's relation in cuprates, suggesting phase-coherence-limited superconductivity. Our results provide strong evidence for nodal superconductivity in TTG and put strong constraints on the mechanisms of these graphene-based superconductors
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