Observation of magnetically switchable quantum geometric photocurrents

In non-centrosymmetric materials, light can be rectified into two types of DC photocurrents, known as injection and shift currents, through the bulk photovoltaic effect. In non-magnetic crystals, where these currents have been routinely observed, the injection current responds to circular light, while the shift current responds to linear light. Magnetic crystals have been predicted to show a new set of hitherto unobserved magnetically switchable photocurrents, with the roles of linear and circular light interchanged. In the presentation, we will demonstrate the existence of such currents in an antiferromagnet, and the switching of the currents by flipping the Néel vector. Our work demonstrates a new way to control photocurrents in magnets that are directly tied to geometry and have promising applications in antiferromagnetic spintronics and light harvesting.