Tunable Tesla-scale magnetic attosecond pulses through ring-current gating

TL;DR

This paper introduces a method to generate highly tunable, ultrafast magnetic pulses using laser-driven electron dynamics, enabling new experiments in ultrafast magnetism and spin physics.

Contribution

The study presents a novel 'current-gating' approach to produce isolated, tunable attosecond magnetic pulses with high flux density, demonstrated through ab-initio calculations.

Findings

Magnetic pulses with durations of 787 attoseconds were achieved.

The magnetic flux density can reach approximately 1 Tesla.

The pulses are highly tunable in waveform and frequency.

Abstract

Coherent control over electron dynamics in atoms and molecules using high-intensity circularly-polarized laser pulses gives rise to current loops, resulting in the emission of magnetic fields. We propose and demonstrate with ab-initio calculations ``current-gating" schemes to generate direct or alternating-current magnetic pulses in the infrared spectral region, with highly tunable waveform and frequency, and showing femtosecond-to-attosecond pulse duration. In optimal conditions, the magnetic pulse can be highly isolated from the driving laser and exhibits a high flux density ($\sim1$ Tesla at few hundred nanometers from the source, with a pulse duration of 787 attoseconds) for application in forefront experiments of ultrafast spectroscopy. Our work paves the way toward the generation of attosecond magnetic fields to probe ultrafast magnetization, chiral responses, and spin dynamics.