Nanoscale UltradenseZ-Pinch Formation from Laser-Irradiated Nanowire Arrays

We show that ultradense Z pinches with nanoscale dimensions can be generated by irradiating aligned nanowires with femtosecond laser pulses of relativistic intensity. Using fully three-dimensional relativistic particle-in-cell simulations, we demonstrate that the laser pulse drives a forward electron current in the area around the wires. This forward current induces return current densities of ~0.1 GA per μm² through the wires. The resulting strong, quasistatic, self-generated azimuthal magnetic field pinches the nanowires into hot plasmas with a peak electron density of >9×10²⁴ cm^-3, exceeding 1000 times the critical density. Arrays of these new ultradense nanopinches can be expected to lead to efficient microfusion and other applications.