Development of a planar penning trap for quantum applications with electrons

Cridland, April Louise (2018) Development of a planar penning trap for quantum applications with electrons. Doctoral thesis (PhD), University of Sussex.

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This thesis presents the development of the Geonium Chip, a planar Penning trap. The Geonium Chip consists of the five electrodes of a cylindrical Penning trap projected onto the surface of a microfabricated chip. Beneath the chip is a planar magnetic field source currently made from coils of niobium titanium wire. Traditionally the magnetic field source is a large superconducting solenoid, replacing this with a planar source makes the setup scalable, portable and economical.

The Geonium Chip, with its magnetic field source and detection electronics, need to be placed in a cryostat. In this thesis, I describe the development of the cryogenic setup with particular emphasis on the design and optimisation of the non-destructive detection system. I detail the cryogenic wiring of the cryostat including the thermalisation of high current wires and the noise reduction techniques employed on the detection signal. In addition, I explore the parasitic capacitances of the Geonium Chip using microwave network analysis and describe the testing of the magnetic field source at 4 K. Finally, I discuss the generation of electrons within the trap and the results of our first attempts at trapping a cloud of electrons.

Together, the chip and the magnetic field source can be used to trap ions for ultraaccurate mass spectrometry or an electron for single microwave photon detection. A single microwave photon detector is a tool that is currently still missing in quantum technology and is needed for determining the quantum state of microwave radiation fields. This is vital for quantum communication and cryptography. Additionally, using the Geonium Chip as a mass spectrometer has the potential to lead to very accurate mass spectrums without the need for frequent calibration. Finally, eliminating the expensive superconducting solenoid will make accurate mass spectrometry available to a wider market.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics > QC0350 Optics. Light > QC0450 Spectroscopy > QC0454.M3 Mass spectroscopy
Depositing User: Library Cataloguing
Date Deposited: 13 Dec 2018 14:45
Last Modified: 13 Dec 2018 14:45

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