Magnetic field stabilization of ultracold atoms using FPGA devices

Project Level: Honours

In our laboratory, our research interest is in understanding the spin and magnetic properties of dilute gases of trapped ultra-cold atoms cooled to nanoKelvin temperatures. Many of the subtle effects we expect to observe, such as transitions between magnetic ordering (eg ferromagnetism), and excitations and vortices in the spin degree of freedom, require careful control and removal of stray background magnetic fields in order to be observed. To this end, we would like to build a magnetic field stabilization system that actively corrects the background field experienced by our trapped cold atoms. The heart of this system will be to use Field Programmable Gate Arrays (FPGA), which are powerful programmable and configurable logic devices. Using fluxgate magnetic probes to measure the field, the FPGA will use appropriate feedback control to minimise and correct for stray DC and AC magnetic fields, applied through controlling the current in biasing coils. Expected outcomes: In this project, we will construct an electronic device that couples the signal from magnetic fluxgate sensors into a programmable FPGA device. The student will gain experience in feedback control, electronic design, coil construction, and programming of FPGA devices. Initially the project will focus on building a demonstration test system, before trying to implement on our experimental apparatus.