Jacques is a pioneer of scanning NV magnetometry, using single nitrogen-vacancy spins in scanning-probe diamond tips to image magnetic textures at the nanoscale under ambient conditions. His team applies this to condensed-matter systems including antiferromagnetic domain walls and chiral spin textures, non-collinear antiferromagnetic order via single-spin relaxometry, and current-driven skyrmion motion in synthetic antiferromagnets, work carried out in close collaboration with materials-physics groups.