Investigating magnetic order in Sr$_{2}$RuO$_{4}$ using cantilever torque magnetometry

Following the initial $\mu $SR and NMR studies suggesting that Sr$_{2}$RuO$_{4}$ is a spin-triplet superconductor, there has been a great deal of interest to understand the nature of the order parameter. Although Sr$_{2}$RuO$_{4}$ is similar in structure to the layered high-Tc cuprate superconductors, it is thought to possess chiral p$_{x}\pm $ip$_{y}$ pairing symmetry. The complex order parameter can give rise to a rich variety of new correlated states, such as domains having orbital order that possess a net magnetic moment and half-integer vortices with zero-energy modes. We have applied ultrasensitive cantilever torque magnetometry to measure the magnetic moment, susceptibility, and vortex entry into micron-size Sr$_{2}$RuO$_{4}$ in search of magnetic moments generated by chiral edge currents and fractional vortices. This talk will present recent data in this effort.