Attosecond-magnetic-field-pulse generation by intense few-cycle circularly polarized UV laser pulses

Abstract

Intense attosecond-magnetic-field pulses are predicted to be produced by intense few-cycle attosecond circularly polarized UV pulses. Numerical solutions of the time-dependent Schr\"odinger equation for H${}_{2}$${}^{+}$ are used to study the electronic dynamical process. Spinning attosecond circular electron wave packets are created on subnanometer molecular dimensions, thus generating attosecond magnetic fields of several tens of Teslas (${10}^{5}$ G). Simulations show that the induced magnetic field is critically dependent on the pulse wavelength $\ensuremath{\lambda}$ and pulse duration $n\ensuremath{\tau}$ ($n$ is number of cycles) as predicted by a classical model. For ultrashort few-cycle circularly polarized attosecond pulses, molecular orientation influences the generation of the induced magnetic fields as a result of preferential ionization perpendicular to the molecular axis. The nonspherical asymmetry of molecules allows for efficient attosecond-magnetic-field-pulse generation.