Implementation of an Ytterbium 171 Trapped Ion Qubit
Thesis (PhD)--Stellenbosch University, 2020.
ENGLISH ABSTRACT: This thesis presents the work done in developing an ion trap lab at Stellenbosch University. A linear Paul trap was assembled under a microscope and geometrically veriﬁed using a laserbeam and a translational stage. A helical resonator and an LC resonator, to be used for generation of the necessary ion trapping potential, were implemented and characterized in detail, both through modeling and measurement. The helical resonator was used to successfully trap our ﬁrst cloud of Doppler cooled Ytterbium ions under ultra-high vacuum conditions. Subsequently single ions were trapped successfully. The work culminated in the demonstration of Rabi oscillations in ytterbium 171 ions, a conﬁrmation that we can operate the ions as qubits. One chapter in this thesis discusses theoretical work done under the atomic clock group at NIST on modeling power law noise which affects, among other things, oscillators and resonators such as lasers and optical cavities by broadening their linewidths. In that model we adapt the Barnes-Jarvis model and Mandlebrot model to generate noise with desired spectral properties. We also show that Barnes-Jarvis model and Mandelbrot models can be transformed into one another using partial fractions in frequency domain. In an attempt to model the noise distribution of power law noise, over a given band of frequencies, we invoke the Gaussian Mixture Models. This theoretical work on power law noise models is of importance to our lab here in Stellenbosch since we have a long history of research in mitigation of decoherence, as well as quantum state monitoring and feedback control, all of which rely strongly on detailed knowledge of the underlying noise processes.