Magnetoelectric Bulk Photovoltaic Effect in Centrosymmetric Solids

Overview & Synopsis

It is commonly believed that a bulk photovoltaic current requires broken spatial inversion symmetry. However, in this work, we demonstrate that dc photocurrents can arise in centrosymmetric solids from the bilinear coupling between the electric and magnetic components of light. This magnetoelectric bulk photovoltaic effect (MBPE) has a quantum-geometric origin in the dipole moments of the Zeeman quantum metric and Zeeman Berry curvature. We identify four distinct MBPE mechanisms, including time-reversal-even and time-reversal-odd injection-like and shift-like photocurrents driven by linearly or circularly polarized light. Our symmetry analysis shows that the MBPE is allowed in broad classes of two-dimensional centrosymmetric nonmagnetic and magnetic materials under normally incident light. As representative examples, we predict sizable MBPEs in centrosymmetric monolayer Pt$_2$HgSe$_3$ and altermagnetic RuF$_4$, with current densities on the order of $1~\mathrm{mA/m}$. Notably, the injection-like photocurrent in RuF$_4$ reverses sign upon switching either the light helicity or the Néel vector. Our results extend the bulk photovoltaic effect to centrosymmetric solids and open new opportunities for electrical readout of altermagnetic order.