Micro-Levitated Electromechanics

Student thesis: Doctoral ThesisDoctor of Philosophy


Levitation of mesoscopic particles in high vacuum provides a promising platform to investigate nanoscale thermodynamics and the boundary between the classical and quantum worlds. By using a microfabricated Paul trap, charged particles with a wide range of sizes and materials can be coupled to the electrodes of the trap, enabling all-electrical levitation and cooling. With this two-way interaction between mesoscopic particles and the trapping electrodes, detection and control of particle motion can be realized. Through passive resistive cooling or active feedback cooling, high precision force detection will be achieved, and there is even the potential to reach the quantum regime. Simulations of the Paul trap using SIMION are conducted. An experimental microfabricated Paul trap has been designed and assembled. In this context, an innovative event-based imaging scheme is introduced to monitor the motion of microparticles, which enables the tracking of multiple particles at higher speed than conventional cameras. In consonance with this methodology, a Field Programmable-Gate-Array(FPGA)-based system is employed to output the detection signal from an event-based imaging scheme in real time. A cooling process based on cold damping is then carried out to reduce the temperature by 4 times at 2×10−2 mbar. A cooling phenomenon is evident in a specific mode during the cooling process of a pair of levitated particles. Furthermore, an electric detection of particle motion is also explored to get a minimum (1.1 ± 0.2) × 10−12 A image current detection. Further improvement of the electric detection is suggested.
Date of Award1 Dec 2023
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorJames Millen (Supervisor) & Mark Green (Supervisor)

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