The nonlinear Hall effect (NHE) is a recently discovered member of the Hall effect family in which the Hall voltage shows a nonlinear behavior when a transverse electric field is applied. While the NHE does not require broken time-reversal symmetry, such as that induced by a magnetic field, it requires broken inversion symmetry, which limits the range of suitable systems and potential applications. Here, we demonstrate an ultrafast NHE in centrosymmetric black phosphorus through dynamical symmetry breaking using femtosecond light pulses. We provide a detailed microscopic picture of excited carrier dynamics and induced fields using momentum-resolved photoemission spectroscopy combined with \textit{ab-initio} calculations. The ultrafast NHE is observed exclusively for the light polarization aligned with the armchair high-symmetry direction and persists over 300 fs, which opens new possibilities for selective and ultrafast light-to-current conversions.
@article{arxiv.2604.06083,
title = {Ultrafast nonlinear Hall effect in black phosphorus},
author = {Maciej Dendzik and Andrea Marini and Samuel Beaulieu and Shuo Dong and Tommaso Pincelli and Julian Maklar and R. Patrick Xian and Enrico Perfetto and Martin Wolf and Gianluca Stefanucci and Ralph Ernstorfer and Laurenz Rettig},
journal= {arXiv preprint arXiv:2604.06083},
year = {2026}
}