A Cantilever Torque Magnetometry Method for the Measurement of Hall Conductivity of Highly Resistive Samples.

We present the first measurements of Hall conductivity utilizing a new torque magnetometry method designed for insulators. A Corbino disk exhibits a magnetic dipole moment proportional to Hall conductivity when voltage is applied across a test material. This magnetic dipole moment can be measured through torque magnetometry. The symmetry of this contactless technique allows for the measurement of Hall conductivity in previously inaccessible materials. Finally, a low-temperature noise bound, the lack of systematic errors on dummy devices, and a measurement of the Hall conductivity of sputtered indium tin oxide demonstrate the efficacy of the technique.