3D printed components for quantum devices

Saint, Reece William (2020) 3D printed components for quantum devices. Doctoral thesis (PhD), University of Sussex.

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Abstract

Since the first demonstrations of laser cooling of atomic vapors in the late 1970s, the field of ultracold atoms has seen rapid advancements in the preparation, control and measurement of atomic gases. Ultra-cold atomic systems, either as individual atoms or in larger ensembles, provide a powerful tool for experimenters. Their large deBroglie wavelengths make them particularly useful for interferometric applications, and their isotropic properties when unperturbed make them ideal candidates for frequency standards. A recent drive has seen experimenters looking to develop scalable, portable and robust atomic systems as a metrological tool outside of the typical laboratory environment. This could see unprecedented sensitivities made available for areas as diverse as GPS-free navigation, biomedical imaging and non-invasive underground mapping.

Over the course of this thesis we explore additive manufacturing (3D printing) as a production technique for quantum technology. 3D-printing offers unrivalled design freedom and rapid prototyping, allowing us to develop a number of printed structures to test the viability of selective laser melting as a technique to produce metallic components that survive within, and also hold, the ultra-high vacuum environment necessary for ultracold physics. The technique has the potential to improve the efficiency and compactness of devices.

We begin first by printing an Al-Si-Mg vacuum flange, which is then solution heat treated in post processing and milled to have a standard vacuum-sealing knife edge on its surface. By installing the flange on a test vacuum set-up, baking out over a week at 200­­­°C and pumping down, a pressure of 10⁻¹¹ mbar is achieved. In the same material, a conductive structure called the cylinder trap is printed as a proof of concept ultracold atom source producing the fields necessary for a magneto-optical trap. A complete cold atom experiment is constructed to test the device, including a simple microcontroller-based control system. Dissipating as little as 20mW electrical power, the atom trap generates 10⁸ atoms with an average temperature on the order of (20.1 ± 0.2)μK, whilst having no measurable effect on the vacuum pressure, measured as < 10⁻¹⁰ mbar.

A next-generation device is then investigated, building on the work of the cylinder trap and consideration of contemporary work on cold-atom sources. This device would output an even colder source of atoms, with a tapered design to both act as a differential pump and for atom compression for transport to a secondary trap. With calculations on optimal trapping regimes, an Ioffe-Pritchard style magnetic trap layout is created to efficiently capture atoms from the magnetooptical trap. Atoms would then be transported through a three-dimensional funnel structure into a secondary magnetic trap where fast, evaporative cooling could occur. Simultaneously the next thermal cloud can be captured to improve the average cycle time. Encouraged by collaborative work on a additively manufactured chamber, called the coral trap, a prototype design is developed and presented consisting of the funnel structure split across a multi-chamber printed architecture.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics > QC0170 Atomic physics. Constitution and properties of matter Including molecular physics, relativity, quantum theory, and solid state physics > QC0174.12 Quantum theory. Quantum mechanics
T Technology > T Technology (General) > T0174.7 Nanotechnology
Depositing User: Library Cataloguing
Date Deposited: 01 Jul 2020 11:21
Last Modified: 01 Jul 2020 11:27
URI: http://sro.sussex.ac.uk/id/eprint/92246

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