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Abstract Turbulent energy dissipation is a fundamental process in plasma physics that has not been settled. It is generally believed that the turbulent energy is dissipated at electron scales leading to electron energization in magnetized plasmas. Here, we propose a micro accelerator which could transform electrons from isotropic distribution to trapped, and then to stream (Strahl) distribution. From the MMS observations of an electron-scale coherent structure in the dayside magnetosheath, we identify an electron flux enhancement region in this structure collocated with an increase of magnetic field strength, which is also closely associated with a non-zero parallel electric field. We propose a trapping model considering a field-aligned electric potential together with the mirror force. The results are consistent with the observed electron fluxes from ~50 eV to ~200 eV. It further demonstrates that bidirectional electron jets can be formed by the hourglass-like magnetic configuration of the structure. 

Abstract The morphology and motion of auroras have been widely studied due to their indications on magnetospheric processes. Here, we report a new kind of “auroral curls,” which have wavelengths in the mesoscale (∼100 km) and propagate azimuthally. Utilizing data from the Chinese Antarctic Zhongshan Station (the all‐sky imager and the high‐frequency radar), the Active Magnetosphere and Planetary Electrodynamics Response Experiment and the Defense Meteorological Satellite Program, we analyze an event occurred on 23 April 2019. We find these curls are fine structures in the poleward boundary of multiple arcs. Corresponding field‐aligned currents manifest as a series of longitudinally arranged pairs, while ionospheric flow velocities nearby oscillate with periods in the Pc 5 band. Observational evidence suggests these curls are connected with ultra‐low frequency (ULF) waves, which opens the possibility of using auroras to globally image ULF waves. 

Abstract The graphene boom has triggered a widespread search for novel elemental van der Waals materials thanks to their simplicity for theoretical modeling and easy access for material growth. Group VI element tellurium is an unintentionally p-type doped narrow bandgap semiconductor featuring a one-dimensional chiral atomic structure which holds great promise for next-generation electronic, optoelectronic, and piezoelectric applications. In this paper, we first review recent progress in synthesizing atomically thin Te two-dimensional (2D) films and one-dimensional (1D) nanowires. Its applications in field-effect transistors and potential for building ultra-scaled Complementary metal–oxide–semiconductor (CMOS) circuits are discussed. We will also overview the recent study on its quantum transport in the 2D limit and progress in exploring its topological features and chiral-related physics. We envision that the breakthrough in obtaining high-quality 2D Te films will inspire a revisit of the fundamental properties of this long-forgotten material in the near future. 

Abstract The inelastic scattering length (L_s) is a length scale of fundamental importance in condensed matters due to the relationship between inelastic scattering and quantum dephasing. In quantum anomalous Hall (QAH) materials, the mesoscopic length scaleL_splays an instrumental role in determining transport properties. Here we examineL_sin three regimes of the QAH system with distinct transport behaviors: the QAH, quantum critical, and insulating regimes. Although the resistance changes by five orders of magnitude when tuning between these distinct electronic phases, scaling analyses indicate a universalL_samong all regimes. Finally, mesoscopic scaled devices with sizes on the order ofL_swere fabricated, enabling the direct detection of the value ofL_sin QAH samples. Our results unveil the fundamental length scale that governs the transport behavior of QAH materials.