Instrumentation design for a thermal Hall measurement device compatible with a Quantum Design PPMS

Thermal Hall measurements are a novel approach to material characterization. It is an exotic measurement technique that can be used to probe heat carriers and scattering mechanisms of different materials. Currently, the race to develop quantum qubits has sparked many methods of creating different types of qubits. This is where utilizing thermal Hall measurements to probe superconducting materials for Majorana zero modes (MZM) comes in. This measurement could provide insight into unique materials that are theorized to host these MZMs which in turn could be used as qubits.

 

To conduct these measurements, a device has been constructed and retrofitted to be used in conjunction with a Quantum Design PPMS via a stripped-down thermal transport option (TTO) puck. Starting with a 3D-printed model and prototype to determine the necessary schematics, a final device has been made using high precision machining and parts that meet the desired specs. This includes a precision machined base made from brass as well as high precision differential thermocouples made from chromel and iron doped gold wires.  We will present the evolution in the instrumentation design as we attempted to resolve emergent issues and improve the device.

 

All of this culminates with calibration measurements on known standard materials such as strontium titanate where the thermal Hall effect has been verified in literature. Through this data we show the success of a working prototype of this thermal Hall device which can be further used for other novel magnetic materials that have yet to be studied using this method.