Probing the limits of quantum mechanics using a cold mechanical force sensor

In this dissertation, we work towards an experiment in which we aim to bring a micrometer sized magnet at the tip of a soft cantilever into a superposition. We propose an experiment in which the magnet is coupled to a single electron which is then brought in a superposition of spin-up and –down. Due to the coupling between the cantilever and the electron spin, the magnet may be brought into a superposition. We describe the experiment, the requirements and our progress towards these requirements. These include measuring the thermal motion of a sub-kHz force sensor below 5 mK and measuring the spin density of a diamond sample using Magnetic Force Microscopy.<br>