Hydrostatic pressure effects on the magnetic excitation spectra of a quasi-two-dimensional S=1 antiferromagnet BaNi2V2O8

In this experiment we propose to study the hydrostatic pressure effects on the magnetic excitation spectra of the S=1 honeycomb antiferromagnet (AFM) BaNi2V2O8 which was shown to be a rare ideal physical realization of a quasi-2D AFM over a wide temperature range. BaNi2V2O8 is particular interesting because it reveals signatures for Berezinskii-Kosterlitz-Thousless (BKT) critical behavior within planar 2D XY regime just above Neel-ordering temperature TN. However, the estimated BKT transition temperature T_BKT in BaNi2V2O8 is lower than the TN, thus the quasi-ordered state of vortex/anti-vortex pairs is hidden by long-range magnetic order so that signatures for the decomposed vortex/anti-vortex pairs can be only experimentally observed just above TN. Therefore, searching for the experimental tool which can affect the Hamiltonian and the planar XY anisotropy to make BKT behavior more experimentally accessible is an interesting scientific task and pressure is a promising candidate.