Cavity-mediated electron-photon superconductivity

We investigate electron paring in a two-dimensional electron system mediated by vacuum fluctuations inside a nanoplasmonic terahertz cavity. We show that the structured cavity vacuum can induce long-range attractive interactions between current fluctuations which lead to pairing in generic materials with critical temperatures in the low-Kelvin regime for realistic parameters. The induced state is a pair density wave superconductor which can show a transition from a fully gapped to a partially gapped phase - akin to the pseudogap phase in high-$T_c$ superconductors. Our findings provide a promising tool for engineering intrinsic electron interactions in two-dimensional materials.Comment: 11 page

Shared Arrangements: practical inter-query sharing for streaming dataflows

Current systems for data-parallel, incremental processing and view maintenance over high-rate streams isolate the execution of independent queries. This creates unwanted redundancy and overhead in the presence of concurrent incrementally maintained queries: each query must independently maintain the same indexed state over the same input streams, and new queries must build this state from scratch before they can begin to emit their first results. This paper introduces shared arrangements: indexed views of maintained state that allow concurrent queries to reuse the same in-memory state without compromising data-parallel performance and scaling. We implement shared arrangements in a modern stream processor and show order-of-magnitude improvements in query response time and resource consumption for interactive queries against high-throughput streams, while also significantly improving performance in other domains including business analytics, graph processing, and program analysis

Igazolt hiányzás? A pull-out tehetséggondozó módszer működése Izraelben

Pedagógusként talán nehéz elképzelni, hogy tehetséges diákok esetében léteznek olyan helyzetek, mikor pedagógiai szempontból az az előnyös, ha a tanulók rendszeresen hiányoznak az iskolából. Sőt, annál nagyobb nyereségre tehetnek szert, minél hosszabb időn át, és minél rendszeresebben, lehetőleg hetente teszik ezt. Természetesen ez a rendszeres „iskolakerülés” nem azt jelenti, hogy ellenőrizetlen körülmények között vesztegetik el az idejüket, hanem épp az ellenkezőjét

Community in the Classroom

Research prior to the COVID-19 pandemic has heavily supported the importance of a classroom environment in which students feel as if they belong. A sense of belonging and inclusion from one’s peers is a basic human need and has been found to increase a student’s engagement in class and, in turn, their academic achievement. As students return to in-person learning, deficits in social and emotional skills of students have been the focus of many teachers in the field, stressing the need for strategies that foster relationships in the classroom. This study was conducted to test whether implementing different community building activities weekly, in addition to the traditional ice breakers used during the first week of school, provided increased benefits for student sense of belonging, sense of engagement, and achievement in the tenth grade life science classroom. The activities used in this study were developed to help students get to know one another and embrace their own individuality. The results of this study found that while student belonging and engagement survey scores did not significant increase from the community building activities conducted, student sense of belonging and engagement did seem to improve based on student interviews. Survey responses were subjective as opposed to concrete achievement scores. That being said, student achievement was found to increase significantly from the implemented community building activities throughout the course of the study

Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results

We investigate the effects of changes in the cosmological parameters between the WMAP 1st, 3rd, and 5th year results on the structure of dark matter haloes. We use a set of simulations that cover 5 decades in halo mass ranging from the scales of dwarf galaxies (V_c ~30 km/s) to clusters of galaxies (V_c ~ 1000 km/s). We find that the concentration mass relation is a power law in all three cosmologies. However the slope is shallower and the zero point is lower moving from WMAP1 to WMAP5 to WMAP3. For haloes of mass log(M_200/Msun) = 10, 12, and 14 the differences in the concentration parameter between WMAP1 and WMAP3 are a factor of 1.55, 1.41, and 1.29, respectively. As we show, this brings the central densities of dark matter haloes in good agreement with the central densities of dwarf and low surface brightness galaxies inferred from their rotation curves, for both the WMAP3 and WMAP5 cosmologies. We also show that none of the existing toy models for the concentration-mass relation can reproduce our simulation results over the entire range of masses probed. In particular, the model of Bullock et al (B01) fails at the higher mass end (M > 1e13 Msun), while the NFW model of Navarro, Frenk & White (1997) fails dramatically at the low mass end (M < 1e12 Msun). We present a new model, based on a simple modification of that of B01, which reproduces the concentration-mass relations in our simulations over the entire range of masses probed (1e10 Msun < M < 1e15 Msun). Haloes in the WMAP3 cosmology (at a fixed mass) are more flatted compared to the WMAP1 cosmology, with a medium to long axis ration reduced by ~10 %. Finally, we show that the distribution of halo spin parameters is the same for all three cosmologies.Comment: 16 pages, 16 figures, references updated, minor changes. Accepted for publication on MNRAS. WMAP5 simulations available upon reques

Terahertz field control of interlayer transport modes in cuprate superconductors

We theoretically show that terahertz pulses with controlled amplitude and frequency can be used to switch between stable transport modes in layered superconductors, modelled as stacks of Josephson junctions. We find pulse shapes that deterministically switch the transport mode between superconducting, resistive and solitonic states. We develop a simple model that explains the switching mechanism as a destablization of the centre of mass excitation of the Josephson phase, made possible by the highly non-linear nature of the light-matter coupling

Reviews

Anne Brockbank, Ian McGill and Nic Beech, Reflective Learning in Practice, Aldershot: Gower Publishing, ISBN: 0 566 08377 9. £49.50