Brownian motion of magnetically levitated microsystems in vacuum

This project aims to study the Brownian motion of a diamond micro-particle in a harmonic trap at pressures as low as 1×10−6 Torr. A novel, purely magnetic trap was designed with three dimensional magnetic modelling, optimising its shape to produce the highest resonant trapping frequencies. Experimental power spectral densities and mean square displacements match the theory very well, clearly showing observation of Brownian motion at low pressure. An attempt is also made to test the energy equipartition theorem at low pressure. There is potential for this trap configuration to be used to as a platform on which a macroscopic quantum superposition of states can be created and maintained oneday. There is also more immediate potential of the miniaturisation and integration of this trap system into electronics as a precision inertial sensor.