Reconnection of magnetic flux ropes driven by two-color Laguerre–Gaussian laser pulses in plasma

The generation and reconnection of magnetic flux ropes in a plasma irradiated by two Laguerre–Gaussian laser pulses with different frequencies and opposite topological charges are investigated numerically by particle-in-cell simulations. It is shown that twisted plasma currents and hence magnetic flux ropes can be effectively generated as long as the laser frequency difference matches the electron plasma frequency. More importantly, subsequent reconnection of magnetic flux ropes can occur. Typical signatures of magnetic reconnection, such as magnetic island formation and plasma heating, are identified in the reconnection of magnetic flux ropes. Notably, it is found that a strong axial magnetic field can be generated on the axis, owing to the azimuthal current induced during the reconnection of the ropes. This indicates that in the reconnection of magnetic flux ropes, the energy can be transferred not only from the magnetic field to the plasma but also from the plasma current back to the magnetic field. This work opens a new avenue to the study of magnetic flux ropes, which helps in understanding magnetic topology changes, and resultant magnetic energy dissipation, plasma heating, and particle acceleration found in solar flares, and magnetic confinement fusion devices.