Probing short-range magnetism in candidate quantum spin liquids and related materials with a "both-and" approach to diffuse neutron scattering data*

Extracting the maximum possible information from diffuse neutron scattering data is an important objective that supports efforts to gain a deeper understanding of the entangled ground states of quantum spin liquids and related materials. Significant progress has been made in the recent past by modeling diffuse magnetic scattering either in reciprocal space or real space using either big-box (e.g. reverse Monte Carlo) or small-box (e.g. magnetic unit cell) models. However, this "either-or" approach may not be as effective as a "both-and" approach that considers the data in both reciprocal space and real space and makes use of both big-box and small-box models in a complementary fashion. The power of the "both-and" approach is highlighted in recent studies of two triangular lattice antiferromagnets: TmMgGaO₄, which is thought to host a Kosterlitz-Thouless phase, and NaYbO₂, a candidate quantum spin liquid. We present diffuse neutron scattering data on both of these systems and demonstrate how the use of complementary modes of analysis reveals important details about the local magnetic correlations that could otherwise be easily missed. In addition to shedding light on the physics of these two interesting systems, this work motivates future "both-and" studies of candidate quantum spin liquids and related materials.