Magnetoresistance and electronic structure of asymmetric GaAs/AlGaAs double quantum wells in the in-plane/tilted magnetic field

Bilayer two-dimensional electron systems formed by a thin barrier in the GaAs buffer of a standard heterostructure were investigated by magnetotransport measurements. In magnetic fields oriented parallel to the electron layers, the magnetoresistance exhibits an oscillation associated with the depopulation of the higher occupied subband and the field-induced transition into a decoupled bilayer. Shubnikov-de Haas oscillations in slightly tilted magnetic fields allow to reconstruct the evolution of the electron concentration in the individual subbands as a function of the in-plane magnetic field. The characteristics of the system derived experimentally are in quantitative agreement with numerical self-consistent-field calculations of the electronic structure.Comment: 6 pages, 5 figure

A deep dive into the ecology of Gamay (Botany Bay, Australia): current knowledge and future priorities for this highly modified coastal waterway

Context: Gamay is a coastal waterway of immense social, cultural and ecological value. Since European settlement, it has become a hub for industrialisation and human modification. There is growing desire for ecosystem-level management of urban waterways, but such efforts are often challenged by a lack of integrated knowledge. Aim and methods: We systematically reviewed published literature and traditional ecological knowledge (TEK), and consulted scientists to produce a review of Gamay that synthesises published knowledge of Gamay’s aquatic ecosystem to identify knowledge gaps and future research opportunities. Key results: We found 577 published resources on Gamay, of which over 70% focused on ecology. Intertidal rocky shores were the most studied habitat, focusing on invertebrate communities. Few studies considered multiple habitats or taxa. Studies investigating cumulative human impacts, long-term trends and habitat connectivity are lacking, and the broader ecological role of artificial substrate as habitat in Gamay is poorly understood. TEK of Gamay remains a significant knowledge gap. Habitat restoration has shown promising results and could provide opportunities to improve affected habitats in the future. Conclusion and implications: This review highlights the extensive amount of knowledge that exists for Gamay, but also identifies key gaps that need to be filled for effective management

Unipolar Complementary Circuits Using Double Electron Layer Tunneling Tansistors

We demonstrate unipolar complementary circuits consisting of a pair of resonant tunneling transistors based on the gate control of 2D-2D interlayer tunneling, where a single transistor - in addition to exhibiting a welldefined negative-differential-resistance can be operated with either positive or negative transconductance. Details of the device operation are analyzed in terms of the quantum capacitance effect and band-bending in a double quantum well structure, and show good agreement with experiment. Application of resonant tunneling complementary logic is discussed by demonstrating complementary static random access memory using two devices connected in series

Magnetoresistance and cyclotron mass in extremely-coupled double quantum wells under in-plane magnetic fields

The authors experimentally investigate the transport properties of an extremely-coupled AlGaAs/GaAs double quantum well, subject to in-plane magnetic fields (B{sub {parallel}}). The coupling of the double quantum well is sufficiently strong that the symmetric-antisymmetric energy gap ({Delta}{sub SAS}) is larger than the Fermi energy (E{sub F}). Thus for all B{sub {parallel}} only the lower energy branch of the dispersion curve is occupied. In contrast to systems with weaker coupling such that {Delta}{sub SAS} < E{sub F} the authors find: (1) only a single feature, a maximum, in the in-plane magnetoresistance, (2) a monotonic increase with B{sub {parallel}} in the cyclotron mass up to 2.2 times the bulk GaAs mass, and (3) an increasing Fermi surface orbit area with B{sub {parallel}}, in good agreement with theoretical predictions

How project groups achieve coordinated action: A model of shared cognitions on time

This chapter addresses how project teams achieve coordinated action, given the diversity in how team members may perceive and value time. Although synchronization of task activities may occur spontaneously through the nonconscious process of entrainment, some work conditions demand that team members pay greater conscious attention to time to coordinate their efforts. We propose that shared cognitions on time – the agreement among team members on the appropriate temporal approach to their collective task – will contribute to the coordination of team members’ actions, particularly in circumstances where nonconscious synchronization of action patterns is unlikely. We suggest that project teams may establish shared cognitions on time through goal setting, temporal planning, and temporal reflexivity