Lower hybrid drift waves driving electron nongyrotropic heating and vortical flows in an electron-scale reconnection layer

Abstract:

We report measurements of lower-hybrid drift waves (LHDW) driving electron heating and vortical flows in an electron-scale reconnection layer under a guide field. Electron preferential perpendicular heating and nongyrotropy predicted by simulations are observed for the first time, providing a potentially fertile ground for further reconnection to occur on the wave spatial scales. The vortical flows generate magnetic field perturbations comparable to the guide field magnitude. The waves primarily propagate along the outflow direction. The measurements reveal a new regime of electron-wave interaction and how this interaction modifies the electron dynamics in the reconnection layer. To address the question of reconnection-onset on the LHDW scale, fully kinetic simulations and state-of-the-art laboratory experiments that resolve the electron response within the wave spatiotemporal scales are required.