Realization of two-sublattice exchange physics in the triangular lattice compound Ba₃Er(BO₃)₃

We successfully synthesized high-quality single-crystal samples of Ba₃Er(BO₃)₃, which is part of the family of triangular lattice compounds. These compounds have been gaining significant attention lately because they hold the promise of revealing unique quantum states of matter. In our experiments, conducted at extremely low temperatures (around 100 millikelvins), we observed intriguing magnetic behavior in Ba₃Er(BO₃)₃. Our theoretical efforts suggest that this behavior may be attributed to the distinct positions of magnetic ions within the crystal lattice. Specifically, the hexagonal lattice spins displayed a curious mix of ferromagnetic and antiferromagnetic tendencies. However, the presence of quantum effects added an extra layer of complexity to our findings, making them all the more fascinating to explore and understand [1].