Multiferroic coupling in bilayer Janus 3R-CrSCl

Two-dimensional (2D) multiferroics with coupled ferroic orders are attractive for reconfigurable and low-power electronics. Here, we report that bilayer Janus CrSCl—modeled via first-principles calculations—exhibits coexisting intrinsic magnetism, sliding ferroelectricity, and ferrovalley polarization across three stacking configurations. In the S–S stacking, interlayer sliding reverses both electric polarization and valley polarization, while simultaneously switching the total magnetic moment. These reversible and strongly coupled order parameters enable electric- and magnetic-field control of four distinct multiferroic states. Our findings establish Janus CrSCl as a promising platform for field-tunable 2D multiferroics and multifunctional device architectures.