Light-induced ultrafast glide-mirror symmetry breaking in black phosphorus

TL;DR

This paper demonstrates ultrafast light-induced breaking of glide-mirror symmetry in black phosphorus using Floquet engineering, revealing rapid control over symmetry and potential pathways to Floquet topological phases.

Contribution

It introduces a method to achieve ultrafast symmetry breaking in black phosphorus via light, advancing the understanding of Floquet engineering in solid-state materials.

Findings

Light induces a full gap at the nodal ring in black phosphorus.

The symmetry breaking occurs only during light exposure and is reversible within 100 fs.

The work suggests potential for ultrafast control of topological phases.

Abstract

Symmetry breaking plays an important role in fields of physics, ranging from particle physics to condensed matter physics. In solid-state materials, phase transitions are deeply linked to the underlying symmetry breakings, resulting in a rich variety of emergent phases. Such symmetry breakings are often induced by controlling the chemical composition and temperature or applying an electric field and strain, etc. In this work, we demonstrate an ultrafast glide-mirror symmetry breaking in black phosphorus through Floquet engineering. Upon near-resonance pumping, a light-induced full gap opening is observed at the glide-mirror symmetry protected nodal ring, suggesting light-induced breaking of the glide-mirror symmetry. Moreover, the full gap is observed only in the presence of the light-field and disappears almost instantaneously ($\ll$100 fs) when the light-field is turned off, suggesting the ultrafast manipulation of the symmetry and its Floquet engineering origin. This work not only demonstrates light-matter interaction as an effective way to realize ultrafast symmetry breaking in solid-state materials, but also moves forward towards the long-sought Floquet topological phases.